{"transactions":[{"id":3144272,"issuer":{"id":359,"kind":"organization","name":"CASTLE BIOSCIENCES INC","symbol":"CSTL"},"owners":[{"id":149130,"kind":"organization","name":"MGC Venture Partners 2013 GP, LLC","position":1,"cik":"0001783292","reported_name":"MGC Venture Partners 2013 GP, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":149131,"kind":"organization","name":"MGC Venture Partners 2013, L.P.","position":2,"cik":"0001572764","reported_name":"MGC Venture Partners 2013, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":149132,"kind":"organization","name":"MGC Venture Partners 2018 GP, LLC","position":3,"cik":"0001783291","reported_name":"MGC Venture Partners 2018 GP, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":149133,"kind":"organization","name":"MGC VENTURE PARTNERS 2018, L.P.","position":4,"cik":"0001745133","reported_name":"MGC VENTURE PARTNERS 2018, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":149134,"kind":"organization","name":"MGC VENTURE PARTNERS QP 2018, L.P.","position":5,"cik":"0001749814","reported_name":"MGC VENTURE PARTNERS QP 2018, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Common Stock","published_at":"2020-05-19T16:05:33.000Z","date":"2020-05-15","kind":"sale","acquired":false,"shares":8117,"price":37.28,"value":302601.76,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"The transactions on this Form 4 were made pursuant to a Rule 10b5-1 plan adopted by MGC Venture Partners 2013, L.P. (\"MGC 2013 LP\") on March 13, 2020."},{"field":"price","element":"transactionPricePerShare","label":"F6","text":"This transaction was executed in multiple trades at prices ranging from $37.00 to $37.50, inclusive. The price reported above reflects the weighted-average sale price. MGC 2013 LP hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F7","text":"Reflects number of shares owned as of May 15, 2020."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Held directly by MGC 2013 LP."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"MGC Venture Partners 2013 GP, LLC (\"MGC 2013 GP\") is the general partner of MGC 2013 LP. MGC Venture Partners 2018 GP, LLC (\"MGC 2018 GP\") is the general partner of MGC Venture Partners 2018, L.P. (\"MGC 2018 LP\") and MGC Venture Partners QP 2018, L.P. (\"MGC QP 2018 LP\"). Each of MGC 2013 LP, MGC 2013 GP, MGC 2018 LP, MGC QP 2018 LP and MGC 2018 GP directly (whether through ownership or position) or indirectly through one or more intermediaries, may be deemed for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, to be the indirect beneficial owner of some or all of the shares owned by MGC 2013 LP, MGC 2018 LP and MGC QP 2018 LP and, therefore, a \"ten percent holder\" hereunder."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F5","text":"Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton and Byron W. Smith are managing directors of MGC 2013 GP and share voting and investment power over the shares held by MGC 2013 LP. Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton, Byron W. Smith, Jay Ferguson and Rob Readnour are managing partners of MGC 2018 GP and share voting and investment power over the shares held by MGC 2018 LP and MGC QP 2018 LP. Each of the reporting persons disclaims beneficial ownership of the shares held by any other reporting persons reported herein, except to the extent of its pecuniary interest therein, and this report shall not be deemed an admission that the reporting persons are the beneficial owners of such securities for purposes of Section 16 or for any other purposes."}],"balance_after":1464020,"source":{"system":"sec-edgar","filing":"0000899243-20-013561","document":"doc4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1783291/000089924320013561/doc4.xml","form_type":"4"}},{"id":3144271,"issuer":{"id":359,"kind":"organization","name":"CASTLE BIOSCIENCES INC","symbol":"CSTL"},"owners":[{"id":149130,"kind":"organization","name":"MGC Venture Partners 2013 GP, LLC","position":1,"cik":"0001783292","reported_name":"MGC Venture Partners 2013 GP, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":149131,"kind":"organization","name":"MGC Venture Partners 2013, L.P.","position":2,"cik":"0001572764","reported_name":"MGC Venture Partners 2013, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":149132,"kind":"organization","name":"MGC Venture Partners 2018 GP, LLC","position":3,"cik":"0001783291","reported_name":"MGC Venture Partners 2018 GP, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":149133,"kind":"organization","name":"MGC VENTURE PARTNERS 2018, L.P.","position":4,"cik":"0001745133","reported_name":"MGC VENTURE PARTNERS 2018, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":149134,"kind":"organization","name":"MGC VENTURE PARTNERS QP 2018, L.P.","position":5,"cik":"0001749814","reported_name":"MGC VENTURE PARTNERS QP 2018, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Common Stock","published_at":"2020-05-19T16:05:33.000Z","date":"2020-05-15","kind":"sale","acquired":false,"shares":13799,"price":36.39,"value":502145.61,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"The transactions on this Form 4 were made pursuant to a Rule 10b5-1 plan adopted by MGC Venture Partners 2013, L.P. (\"MGC 2013 LP\") on March 13, 2020."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"This transaction was executed in multiple trades at prices ranging from $36.00 to $36.98, inclusive. The price reported above reflects the weighted-average sale price. MGC 2013 LP hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Held directly by MGC 2013 LP."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"MGC Venture Partners 2013 GP, LLC (\"MGC 2013 GP\") is the general partner of MGC 2013 LP. MGC Venture Partners 2018 GP, LLC (\"MGC 2018 GP\") is the general partner of MGC Venture Partners 2018, L.P. (\"MGC 2018 LP\") and MGC Venture Partners QP 2018, L.P. (\"MGC QP 2018 LP\"). Each of MGC 2013 LP, MGC 2013 GP, MGC 2018 LP, MGC QP 2018 LP and MGC 2018 GP directly (whether through ownership or position) or indirectly through one or more intermediaries, may be deemed for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, to be the indirect beneficial owner of some or all of the shares owned by MGC 2013 LP, MGC 2018 LP and MGC QP 2018 LP and, therefore, a \"ten percent holder\" hereunder."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F5","text":"Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton and Byron W. Smith are managing directors of MGC 2013 GP and share voting and investment power over the shares held by MGC 2013 LP. Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton, Byron W. Smith, Jay Ferguson and Rob Readnour are managing partners of MGC 2018 GP and share voting and investment power over the shares held by MGC 2018 LP and MGC QP 2018 LP. Each of the reporting persons disclaims beneficial ownership of the shares held by any other reporting persons reported herein, except to the extent of its pecuniary interest therein, and this report shall not be deemed an admission that the reporting persons are the beneficial owners of such securities for purposes of Section 16 or for any other purposes."}],"balance_after":1472137,"source":{"system":"sec-edgar","filing":"0000899243-20-013561","document":"doc4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1783291/000089924320013561/doc4.xml","form_type":"4"}},{"id":3149920,"issuer":{"id":359,"kind":"organization","name":"CASTLE BIOSCIENCES INC","symbol":"CSTL"},"owners":[{"id":149130,"kind":"organization","name":"MGC Venture Partners 2013 GP, LLC","position":1,"cik":"0001783292","reported_name":"MGC Venture Partners 2013 GP, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":149131,"kind":"organization","name":"MGC Venture Partners 2013, L.P.","position":2,"cik":"0001572764","reported_name":"MGC Venture Partners 2013, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":149132,"kind":"organization","name":"MGC Venture Partners 2018 GP, LLC","position":3,"cik":"0001783291","reported_name":"MGC Venture Partners 2018 GP, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":149133,"kind":"organization","name":"MGC VENTURE PARTNERS 2018, L.P.","position":4,"cik":"0001745133","reported_name":"MGC VENTURE PARTNERS 2018, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":149134,"kind":"organization","name":"MGC VENTURE PARTNERS QP 2018, L.P.","position":5,"cik":"0001749814","reported_name":"MGC VENTURE PARTNERS QP 2018, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Common Stock","published_at":"2020-05-14T16:26:48.000Z","date":"2020-05-13","kind":"sale","acquired":false,"shares":1131,"price":36.08,"value":40806.48,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"The transactions on this Form 4 were made pursuant to a Rule 10b5-1 plan adopted by MGC Venture Partners 2013, L.P. (\"MGC 2013 LP\") on March 13, 2020."},{"field":"price","element":"transactionPricePerShare","label":"F7","text":"This transaction was executed in multiple trades at prices ranging from $36.00 to $36.45, inclusive. The price reported above reflects the weighted-average sale price. MGC 2013 LP hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Held directly by MGC 2013 LP."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"MGC Venture Partners 2013 GP, LLC (\"MGC 2013 GP\") is the general partner of MGC 2013 LP. MGC Venture Partners 2018 GP, LLC (\"MGC 2018 GP\") is the general partner of MGC Venture Partners 2018, L.P. (\"MGC 2018 LP\") and MGC Venture Partners QP 2018, L.P. (\"MGC QP 2018 LP\"). Each of MGC 2013 LP, MGC 2013 GP, MGC 2018 LP, MGC QP 2018 LP and MGC 2018 GP directly (whether through ownership or position) or indirectly through one or more intermediaries, may be deemed for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, to be the indirect beneficial owner of some or all of the shares owned by MGC 2013 LP, MGC 2018 LP and MGC QP 2018 LP and, therefore, a \"ten percent holder\" hereunder."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F5","text":"Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton and Byron W. Smith are managing directors of MGC 2013 GP and share voting and investment power over the shares held by MGC 2013 LP. Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton, Byron W. Smith, Jay Ferguson and Rob Readnour are managing partners of MGC 2018 GP and share voting and investment power over the shares held by MGC 2018 LP and MGC QP 2018 LP. Each of the reporting persons disclaims beneficial ownership of the shares held by any other reporting persons reported herein, except to the extent of its pecuniary interest therein, and this report shall not be deemed an admission that the reporting persons are the beneficial owners of such securities for purposes of Section 16 or for any other purposes."}],"balance_after":1485936,"source":{"system":"sec-edgar","filing":"0000899243-20-013082","document":"doc4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1783291/000089924320013082/doc4.xml","form_type":"4"}},{"id":3149919,"issuer":{"id":359,"kind":"organization","name":"CASTLE BIOSCIENCES INC","symbol":"CSTL"},"owners":[{"id":149130,"kind":"organization","name":"MGC Venture Partners 2013 GP, LLC","position":1,"cik":"0001783292","reported_name":"MGC Venture Partners 2013 GP, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":149131,"kind":"organization","name":"MGC Venture Partners 2013, L.P.","position":2,"cik":"0001572764","reported_name":"MGC Venture Partners 2013, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":149132,"kind":"organization","name":"MGC Venture Partners 2018 GP, LLC","position":3,"cik":"0001783291","reported_name":"MGC Venture Partners 2018 GP, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":149133,"kind":"organization","name":"MGC VENTURE PARTNERS 2018, L.P.","position":4,"cik":"0001745133","reported_name":"MGC VENTURE PARTNERS 2018, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":149134,"kind":"organization","name":"MGC VENTURE PARTNERS QP 2018, L.P.","position":5,"cik":"0001749814","reported_name":"MGC VENTURE PARTNERS QP 2018, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Common Stock","published_at":"2020-05-14T16:26:48.000Z","date":"2020-05-12","kind":"sale","acquired":false,"shares":4601,"price":37.46,"value":172353.46,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"The transactions on this Form 4 were made pursuant to a Rule 10b5-1 plan adopted by MGC Venture Partners 2013, L.P. (\"MGC 2013 LP\") on March 13, 2020."},{"field":"price","element":"transactionPricePerShare","label":"F6","text":"This transaction was executed in multiple trades at prices ranging from $37.00 to $37.98, inclusive. The price reported above reflects the weighted-average sale price. MGC 2013 LP hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Held directly by MGC 2013 LP."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"MGC Venture Partners 2013 GP, LLC (\"MGC 2013 GP\") is the general partner of MGC 2013 LP. MGC Venture Partners 2018 GP, LLC (\"MGC 2018 GP\") is the general partner of MGC Venture Partners 2018, L.P. (\"MGC 2018 LP\") and MGC Venture Partners QP 2018, L.P. (\"MGC QP 2018 LP\"). Each of MGC 2013 LP, MGC 2013 GP, MGC 2018 LP, MGC QP 2018 LP and MGC 2018 GP directly (whether through ownership or position) or indirectly through one or more intermediaries, may be deemed for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, to be the indirect beneficial owner of some or all of the shares owned by MGC 2013 LP, MGC 2018 LP and MGC QP 2018 LP and, therefore, a \"ten percent holder\" hereunder."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F5","text":"Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton and Byron W. Smith are managing directors of MGC 2013 GP and share voting and investment power over the shares held by MGC 2013 LP. Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton, Byron W. Smith, Jay Ferguson and Rob Readnour are managing partners of MGC 2018 GP and share voting and investment power over the shares held by MGC 2018 LP and MGC QP 2018 LP. Each of the reporting persons disclaims beneficial ownership of the shares held by any other reporting persons reported herein, except to the extent of its pecuniary interest therein, and this report shall not be deemed an admission that the reporting persons are the beneficial owners of such securities for purposes of Section 16 or for any other purposes."}],"balance_after":1487067,"source":{"system":"sec-edgar","filing":"0000899243-20-013082","document":"doc4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1783291/000089924320013082/doc4.xml","form_type":"4"}},{"id":3149918,"issuer":{"id":359,"kind":"organization","name":"CASTLE BIOSCIENCES INC","symbol":"CSTL"},"owners":[{"id":149130,"kind":"organization","name":"MGC Venture Partners 2013 GP, LLC","position":1,"cik":"0001783292","reported_name":"MGC Venture Partners 2013 GP, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":149131,"kind":"organization","name":"MGC Venture Partners 2013, L.P.","position":2,"cik":"0001572764","reported_name":"MGC Venture Partners 2013, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":149132,"kind":"organization","name":"MGC Venture Partners 2018 GP, LLC","position":3,"cik":"0001783291","reported_name":"MGC Venture Partners 2018 GP, LLC","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":149133,"kind":"organization","name":"MGC VENTURE PARTNERS 2018, L.P.","position":4,"cik":"0001745133","reported_name":"MGC VENTURE PARTNERS 2018, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}},{"id":149134,"kind":"organization","name":"MGC VENTURE PARTNERS QP 2018, L.P.","position":5,"cik":"0001749814","reported_name":"MGC VENTURE PARTNERS QP 2018, L.P.","relationship":{"director":false,"officer":false,"ten_percent_owner":true,"other":false}}],"security":"Common Stock","published_at":"2020-05-14T16:26:48.000Z","date":"2020-05-12","kind":"sale","acquired":false,"shares":5187,"price":36.61,"value":189896.07,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"The transactions on this Form 4 were made pursuant to a Rule 10b5-1 plan adopted by MGC Venture Partners 2013, L.P. (\"MGC 2013 LP\") on March 13, 2020."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"This transaction was executed in multiple trades at prices ranging from $36.00 to $36.96, inclusive. The price reported above reflects the weighted-average sale price. MGC 2013 LP hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Held directly by MGC 2013 LP."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"MGC Venture Partners 2013 GP, LLC (\"MGC 2013 GP\") is the general partner of MGC 2013 LP. MGC Venture Partners 2018 GP, LLC (\"MGC 2018 GP\") is the general partner of MGC Venture Partners 2018, L.P. (\"MGC 2018 LP\") and MGC Venture Partners QP 2018, L.P. (\"MGC QP 2018 LP\"). Each of MGC 2013 LP, MGC 2013 GP, MGC 2018 LP, MGC QP 2018 LP and MGC 2018 GP directly (whether through ownership or position) or indirectly through one or more intermediaries, may be deemed for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, to be the indirect beneficial owner of some or all of the shares owned by MGC 2013 LP, MGC 2018 LP and MGC QP 2018 LP and, therefore, a \"ten percent holder\" hereunder."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F5","text":"Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton and Byron W. Smith are managing directors of MGC 2013 GP and share voting and investment power over the shares held by MGC 2013 LP. Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton, Byron W. Smith, Jay Ferguson and Rob Readnour are managing partners of MGC 2018 GP and share voting and investment power over the shares held by MGC 2018 LP and MGC QP 2018 LP. Each of the reporting persons disclaims beneficial ownership of the shares held by any other reporting persons reported herein, except to the extent of its pecuniary interest therein, and this report shall not be deemed an admission that the reporting persons are the beneficial owners of such securities for purposes of Section 16 or for any other purposes."}],"balance_after":1491668,"source":{"system":"sec-edgar","filing":"0000899243-20-013082","document":"doc4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1783291/000089924320013082/doc4.xml","form_type":"4"}},{"id":3452766,"issuer":{"id":359,"kind":"organization","name":"CASTLE BIOSCIENCES INC","symbol":"CSTL"},"owners":[{"id":149130,"kind":"organization","name":"MGC Venture Partners 2013 GP, LLC","position":1,"cik":"0001783292","reported_name":"MGC Venture Partners 2013 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149131,"kind":"organization","name":"MGC Venture Partners 2013, L.P.","position":2,"cik":"0001572764","reported_name":"MGC Venture Partners 2013, L.P.","relationship":{"ten_percent_owner":true}},{"id":149132,"kind":"organization","name":"MGC Venture Partners 2018 GP, LLC","position":3,"cik":"0001783291","reported_name":"MGC Venture Partners 2018 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149133,"kind":"organization","name":"MGC VENTURE PARTNERS 2018, L.P.","position":4,"cik":"0001745133","reported_name":"MGC VENTURE PARTNERS 2018, L.P.","relationship":{"ten_percent_owner":true}},{"id":149134,"kind":"organization","name":"MGC VENTURE PARTNERS QP 2018, L.P.","position":5,"cik":"0001749814","reported_name":"MGC VENTURE PARTNERS QP 2018, L.P.","relationship":{"ten_percent_owner":true}}],"security":"Convertible Promissory Note","published_at":"2019-07-31T17:57:31.000Z","date":"2019-07-29","kind":"exercise","acquired":false,"shares":1200000,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F6","text":"The principal amount of the Convertible Promissory Note held by the designated Reporting Person was $1,200,000.00. Upon closing of the IPO, all unpaid principal and accrued interest outstanding on the Convertible Promissory Note (the \"Conversion Amount\") automatically converted into the number of shares of Common Stock equal to the Conversion Amount as of the date immediately prior to the closing date divided by 80% of the IPO price per share of $16.00 per share."},{"field":"shares","element":"transactionShares","label":"F6","text":"The principal amount of the Convertible Promissory Note held by the designated Reporting Person was $1,200,000.00. Upon closing of the IPO, all unpaid principal and accrued interest outstanding on the Convertible Promissory Note (the \"Conversion Amount\") automatically converted into the number of shares of Common Stock equal to the Conversion Amount as of the date immediately prior to the closing date divided by 80% of the IPO price per share of $16.00 per share."},{"field":"price","element":"transactionPricePerShare","label":"F6","text":"The principal amount of the Convertible Promissory Note held by the designated Reporting Person was $1,200,000.00. Upon closing of the IPO, all unpaid principal and accrued interest outstanding on the Convertible Promissory Note (the \"Conversion Amount\") automatically converted into the number of shares of Common Stock equal to the Conversion Amount as of the date immediately prior to the closing date divided by 80% of the IPO price per share of $16.00 per share."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F6","text":"The principal amount of the Convertible Promissory Note held by the designated Reporting Person was $1,200,000.00. Upon closing of the IPO, all unpaid principal and accrued interest outstanding on the Convertible Promissory Note (the \"Conversion Amount\") automatically converted into the number of shares of Common Stock equal to the Conversion Amount as of the date immediately prior to the closing date divided by 80% of the IPO price per share of $16.00 per share."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F6","text":"The principal amount of the Convertible Promissory Note held by the designated Reporting Person was $1,200,000.00. Upon closing of the IPO, all unpaid principal and accrued interest outstanding on the Convertible Promissory Note (the \"Conversion Amount\") automatically converted into the number of shares of Common Stock equal to the Conversion Amount as of the date immediately prior to the closing date divided by 80% of the IPO price per share of $16.00 per share."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Held directly by MGC 2013 LP."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"MGC Venture Partners 2013 GP, LLC (\"MGC 2013 GP\") is the general partner of MGC 2013 LP. MGC Venture Partners 2018 GP, LLC (\"MGC 2018 GP\") is the general partner of MGC Venture Partners 2018, L.P. (\"MGC 2018 LP\") and MGC Venture Partners QP 2018, L.P. (\"MGC QP 2018 LP\"). Each of MGC 2013 LP, MGC 2013 GP, MGC 2018 LP, MGC QP 2018 LP and MGC 2018 GP directly (whether through ownership or position) or indirectly through one or more intermediaries, may be deemed for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, to be the indirect beneficial owner of some or all of the shares owned by MGC 2013 LP, MGC 2018 LP and MGC QP 2018 LP and, therefore, a \"ten percent holder\" hereunder."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F5","text":"Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton and Byron W. Smith are managing directors of MGC 2013 GP and share voting and investment power over the shares held by MGC 2013 LP. Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton, Byron W. Smith, Jay Ferguson and Rob Readnour are managing partners of MGC 2018 GP and share voting and investment power over the shares held by MGC 2018 LP and MGC QP 2018 LP. Each of the Reporting Persons disclaims beneficial ownership of the shares held by any other Reporting Persons reported herein, except to the extent of its pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Persons are the beneficial owners of such securities for purposes of Section 16 or for any other purposes."}],"balance_after":0,"derivative":{"exercise_price":12.8,"underlying":"Common Stock","underlying_shares":97428},"source":{"system":"sec-edgar","filing":"0001140361-19-013900","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":12,"url":"https://www.sec.gov/Archives/edgar/data/1783291/000114036119013900/form4.xml","form_type":"4"}},{"id":3452765,"issuer":{"id":359,"kind":"organization","name":"CASTLE BIOSCIENCES INC","symbol":"CSTL"},"owners":[{"id":149130,"kind":"organization","name":"MGC Venture Partners 2013 GP, LLC","position":1,"cik":"0001783292","reported_name":"MGC Venture Partners 2013 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149131,"kind":"organization","name":"MGC Venture Partners 2013, L.P.","position":2,"cik":"0001572764","reported_name":"MGC Venture Partners 2013, L.P.","relationship":{"ten_percent_owner":true}},{"id":149132,"kind":"organization","name":"MGC Venture Partners 2018 GP, LLC","position":3,"cik":"0001783291","reported_name":"MGC Venture Partners 2018 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149133,"kind":"organization","name":"MGC VENTURE PARTNERS 2018, L.P.","position":4,"cik":"0001745133","reported_name":"MGC VENTURE PARTNERS 2018, L.P.","relationship":{"ten_percent_owner":true}},{"id":149134,"kind":"organization","name":"MGC VENTURE PARTNERS QP 2018, L.P.","position":5,"cik":"0001749814","reported_name":"MGC VENTURE PARTNERS QP 2018, L.P.","relationship":{"ten_percent_owner":true}}],"security":"Series F Preferred Stock","published_at":"2019-07-31T17:57:31.000Z","date":"2019-07-29","kind":"exercise","acquired":false,"shares":507762,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Held directly by MGC 2013 LP."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"MGC Venture Partners 2013 GP, LLC (\"MGC 2013 GP\") is the general partner of MGC 2013 LP. MGC Venture Partners 2018 GP, LLC (\"MGC 2018 GP\") is the general partner of MGC Venture Partners 2018, L.P. (\"MGC 2018 LP\") and MGC Venture Partners QP 2018, L.P. (\"MGC QP 2018 LP\"). Each of MGC 2013 LP, MGC 2013 GP, MGC 2018 LP, MGC QP 2018 LP and MGC 2018 GP directly (whether through ownership or position) or indirectly through one or more intermediaries, may be deemed for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, to be the indirect beneficial owner of some or all of the shares owned by MGC 2013 LP, MGC 2018 LP and MGC QP 2018 LP and, therefore, a \"ten percent holder\" hereunder."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F5","text":"Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton and Byron W. Smith are managing directors of MGC 2013 GP and share voting and investment power over the shares held by MGC 2013 LP. Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton, Byron W. Smith, Jay Ferguson and Rob Readnour are managing partners of MGC 2018 GP and share voting and investment power over the shares held by MGC 2018 LP and MGC QP 2018 LP. Each of the Reporting Persons disclaims beneficial ownership of the shares held by any other Reporting Persons reported herein, except to the extent of its pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Persons are the beneficial owners of such securities for purposes of Section 16 or for any other purposes."}],"balance_after":0,"derivative":{"underlying":"CommonStock","underlying_shares":416537},"source":{"system":"sec-edgar","filing":"0001140361-19-013900","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":11,"url":"https://www.sec.gov/Archives/edgar/data/1783291/000114036119013900/form4.xml","form_type":"4"}},{"id":3452764,"issuer":{"id":359,"kind":"organization","name":"CASTLE BIOSCIENCES INC","symbol":"CSTL"},"owners":[{"id":149130,"kind":"organization","name":"MGC Venture Partners 2013 GP, LLC","position":1,"cik":"0001783292","reported_name":"MGC Venture Partners 2013 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149131,"kind":"organization","name":"MGC Venture Partners 2013, L.P.","position":2,"cik":"0001572764","reported_name":"MGC Venture Partners 2013, L.P.","relationship":{"ten_percent_owner":true}},{"id":149132,"kind":"organization","name":"MGC Venture Partners 2018 GP, LLC","position":3,"cik":"0001783291","reported_name":"MGC Venture Partners 2018 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149133,"kind":"organization","name":"MGC VENTURE PARTNERS 2018, L.P.","position":4,"cik":"0001745133","reported_name":"MGC VENTURE PARTNERS 2018, L.P.","relationship":{"ten_percent_owner":true}},{"id":149134,"kind":"organization","name":"MGC VENTURE PARTNERS QP 2018, L.P.","position":5,"cik":"0001749814","reported_name":"MGC VENTURE PARTNERS QP 2018, L.P.","relationship":{"ten_percent_owner":true}}],"security":"Series E-3 Preferred Stock","published_at":"2019-07-31T17:57:31.000Z","date":"2019-07-29","kind":"exercise","acquired":false,"shares":142843,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Held directly by MGC 2013 LP."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"MGC Venture Partners 2013 GP, LLC (\"MGC 2013 GP\") is the general partner of MGC 2013 LP. MGC Venture Partners 2018 GP, LLC (\"MGC 2018 GP\") is the general partner of MGC Venture Partners 2018, L.P. (\"MGC 2018 LP\") and MGC Venture Partners QP 2018, L.P. (\"MGC QP 2018 LP\"). Each of MGC 2013 LP, MGC 2013 GP, MGC 2018 LP, MGC QP 2018 LP and MGC 2018 GP directly (whether through ownership or position) or indirectly through one or more intermediaries, may be deemed for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, to be the indirect beneficial owner of some or all of the shares owned by MGC 2013 LP, MGC 2018 LP and MGC QP 2018 LP and, therefore, a \"ten percent holder\" hereunder."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F5","text":"Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton and Byron W. Smith are managing directors of MGC 2013 GP and share voting and investment power over the shares held by MGC 2013 LP. Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton, Byron W. Smith, Jay Ferguson and Rob Readnour are managing partners of MGC 2018 GP and share voting and investment power over the shares held by MGC 2018 LP and MGC QP 2018 LP. Each of the Reporting Persons disclaims beneficial ownership of the shares held by any other Reporting Persons reported herein, except to the extent of its pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Persons are the beneficial owners of such securities for purposes of Section 16 or for any other purposes."}],"balance_after":0,"derivative":{"underlying":"CommonStock","underlying_shares":117180},"source":{"system":"sec-edgar","filing":"0001140361-19-013900","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":10,"url":"https://www.sec.gov/Archives/edgar/data/1783291/000114036119013900/form4.xml","form_type":"4"}},{"id":3452763,"issuer":{"id":359,"kind":"organization","name":"CASTLE BIOSCIENCES INC","symbol":"CSTL"},"owners":[{"id":149130,"kind":"organization","name":"MGC Venture Partners 2013 GP, LLC","position":1,"cik":"0001783292","reported_name":"MGC Venture Partners 2013 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149131,"kind":"organization","name":"MGC Venture Partners 2013, L.P.","position":2,"cik":"0001572764","reported_name":"MGC Venture Partners 2013, L.P.","relationship":{"ten_percent_owner":true}},{"id":149132,"kind":"organization","name":"MGC Venture Partners 2018 GP, LLC","position":3,"cik":"0001783291","reported_name":"MGC Venture Partners 2018 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149133,"kind":"organization","name":"MGC VENTURE PARTNERS 2018, L.P.","position":4,"cik":"0001745133","reported_name":"MGC VENTURE PARTNERS 2018, L.P.","relationship":{"ten_percent_owner":true}},{"id":149134,"kind":"organization","name":"MGC VENTURE PARTNERS QP 2018, L.P.","position":5,"cik":"0001749814","reported_name":"MGC VENTURE PARTNERS QP 2018, L.P.","relationship":{"ten_percent_owner":true}}],"security":"Series E-2 Preferred Stock","published_at":"2019-07-31T17:57:31.000Z","date":"2019-07-29","kind":"exercise","acquired":false,"shares":158379,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Held directly by MGC 2013 LP."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"MGC Venture Partners 2013 GP, LLC (\"MGC 2013 GP\") is the general partner of MGC 2013 LP. MGC Venture Partners 2018 GP, LLC (\"MGC 2018 GP\") is the general partner of MGC Venture Partners 2018, L.P. (\"MGC 2018 LP\") and MGC Venture Partners QP 2018, L.P. (\"MGC QP 2018 LP\"). Each of MGC 2013 LP, MGC 2013 GP, MGC 2018 LP, MGC QP 2018 LP and MGC 2018 GP directly (whether through ownership or position) or indirectly through one or more intermediaries, may be deemed for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, to be the indirect beneficial owner of some or all of the shares owned by MGC 2013 LP, MGC 2018 LP and MGC QP 2018 LP and, therefore, a \"ten percent holder\" hereunder."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F5","text":"Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton and Byron W. Smith are managing directors of MGC 2013 GP and share voting and investment power over the shares held by MGC 2013 LP. Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton, Byron W. Smith, Jay Ferguson and Rob Readnour are managing partners of MGC 2018 GP and share voting and investment power over the shares held by MGC 2018 LP and MGC QP 2018 LP. Each of the Reporting Persons disclaims beneficial ownership of the shares held by any other Reporting Persons reported herein, except to the extent of its pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Persons are the beneficial owners of such securities for purposes of Section 16 or for any other purposes."}],"balance_after":0,"derivative":{"underlying":"CommonStock","underlying_shares":129925},"source":{"system":"sec-edgar","filing":"0001140361-19-013900","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":9,"url":"https://www.sec.gov/Archives/edgar/data/1783291/000114036119013900/form4.xml","form_type":"4"}},{"id":3452762,"issuer":{"id":359,"kind":"organization","name":"CASTLE BIOSCIENCES INC","symbol":"CSTL"},"owners":[{"id":149130,"kind":"organization","name":"MGC Venture Partners 2013 GP, LLC","position":1,"cik":"0001783292","reported_name":"MGC Venture Partners 2013 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149131,"kind":"organization","name":"MGC Venture Partners 2013, L.P.","position":2,"cik":"0001572764","reported_name":"MGC Venture Partners 2013, L.P.","relationship":{"ten_percent_owner":true}},{"id":149132,"kind":"organization","name":"MGC Venture Partners 2018 GP, LLC","position":3,"cik":"0001783291","reported_name":"MGC Venture Partners 2018 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149133,"kind":"organization","name":"MGC VENTURE PARTNERS 2018, L.P.","position":4,"cik":"0001745133","reported_name":"MGC VENTURE PARTNERS 2018, L.P.","relationship":{"ten_percent_owner":true}},{"id":149134,"kind":"organization","name":"MGC VENTURE PARTNERS QP 2018, L.P.","position":5,"cik":"0001749814","reported_name":"MGC VENTURE PARTNERS QP 2018, L.P.","relationship":{"ten_percent_owner":true}}],"security":"Series E-1 Preferred Stock","published_at":"2019-07-31T17:57:31.000Z","date":"2019-07-29","kind":"exercise","acquired":false,"shares":463453,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Held directly by MGC 2013 LP."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"MGC Venture Partners 2013 GP, LLC (\"MGC 2013 GP\") is the general partner of MGC 2013 LP. MGC Venture Partners 2018 GP, LLC (\"MGC 2018 GP\") is the general partner of MGC Venture Partners 2018, L.P. (\"MGC 2018 LP\") and MGC Venture Partners QP 2018, L.P. (\"MGC QP 2018 LP\"). Each of MGC 2013 LP, MGC 2013 GP, MGC 2018 LP, MGC QP 2018 LP and MGC 2018 GP directly (whether through ownership or position) or indirectly through one or more intermediaries, may be deemed for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, to be the indirect beneficial owner of some or all of the shares owned by MGC 2013 LP, MGC 2018 LP and MGC QP 2018 LP and, therefore, a \"ten percent holder\" hereunder."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F5","text":"Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton and Byron W. Smith are managing directors of MGC 2013 GP and share voting and investment power over the shares held by MGC 2013 LP. Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton, Byron W. Smith, Jay Ferguson and Rob Readnour are managing partners of MGC 2018 GP and share voting and investment power over the shares held by MGC 2018 LP and MGC QP 2018 LP. Each of the Reporting Persons disclaims beneficial ownership of the shares held by any other Reporting Persons reported herein, except to the extent of its pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Persons are the beneficial owners of such securities for purposes of Section 16 or for any other purposes."}],"balance_after":0,"derivative":{"underlying":"CommonStock","underlying_shares":380190},"source":{"system":"sec-edgar","filing":"0001140361-19-013900","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":8,"url":"https://www.sec.gov/Archives/edgar/data/1783291/000114036119013900/form4.xml","form_type":"4"}},{"id":3452761,"issuer":{"id":359,"kind":"organization","name":"CASTLE BIOSCIENCES INC","symbol":"CSTL"},"owners":[{"id":149130,"kind":"organization","name":"MGC Venture Partners 2013 GP, LLC","position":1,"cik":"0001783292","reported_name":"MGC Venture Partners 2013 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149131,"kind":"organization","name":"MGC Venture Partners 2013, L.P.","position":2,"cik":"0001572764","reported_name":"MGC Venture Partners 2013, L.P.","relationship":{"ten_percent_owner":true}},{"id":149132,"kind":"organization","name":"MGC Venture Partners 2018 GP, LLC","position":3,"cik":"0001783291","reported_name":"MGC Venture Partners 2018 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149133,"kind":"organization","name":"MGC VENTURE PARTNERS 2018, L.P.","position":4,"cik":"0001745133","reported_name":"MGC VENTURE PARTNERS 2018, L.P.","relationship":{"ten_percent_owner":true}},{"id":149134,"kind":"organization","name":"MGC VENTURE PARTNERS QP 2018, L.P.","position":5,"cik":"0001749814","reported_name":"MGC VENTURE PARTNERS QP 2018, L.P.","relationship":{"ten_percent_owner":true}}],"security":"Series D Preferred Stock","published_at":"2019-07-31T17:57:31.000Z","date":"2019-07-29","kind":"exercise","acquired":false,"shares":337754,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Held directly by MGC 2013 LP."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"MGC Venture Partners 2013 GP, LLC (\"MGC 2013 GP\") is the general partner of MGC 2013 LP. MGC Venture Partners 2018 GP, LLC (\"MGC 2018 GP\") is the general partner of MGC Venture Partners 2018, L.P. (\"MGC 2018 LP\") and MGC Venture Partners QP 2018, L.P. (\"MGC QP 2018 LP\"). Each of MGC 2013 LP, MGC 2013 GP, MGC 2018 LP, MGC QP 2018 LP and MGC 2018 GP directly (whether through ownership or position) or indirectly through one or more intermediaries, may be deemed for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, to be the indirect beneficial owner of some or all of the shares owned by MGC 2013 LP, MGC 2018 LP and MGC QP 2018 LP and, therefore, a \"ten percent holder\" hereunder."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F5","text":"Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton and Byron W. Smith are managing directors of MGC 2013 GP and share voting and investment power over the shares held by MGC 2013 LP. Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton, Byron W. Smith, Jay Ferguson and Rob Readnour are managing partners of MGC 2018 GP and share voting and investment power over the shares held by MGC 2018 LP and MGC QP 2018 LP. Each of the Reporting Persons disclaims beneficial ownership of the shares held by any other Reporting Persons reported herein, except to the extent of its pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Persons are the beneficial owners of such securities for purposes of Section 16 or for any other purposes."}],"balance_after":0,"derivative":{"underlying":"CommonStock","underlying_shares":277074},"source":{"system":"sec-edgar","filing":"0001140361-19-013900","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":7,"url":"https://www.sec.gov/Archives/edgar/data/1783291/000114036119013900/form4.xml","form_type":"4"}},{"id":3452760,"issuer":{"id":359,"kind":"organization","name":"CASTLE BIOSCIENCES INC","symbol":"CSTL"},"owners":[{"id":149130,"kind":"organization","name":"MGC Venture Partners 2013 GP, LLC","position":1,"cik":"0001783292","reported_name":"MGC Venture Partners 2013 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149131,"kind":"organization","name":"MGC Venture Partners 2013, L.P.","position":2,"cik":"0001572764","reported_name":"MGC Venture Partners 2013, L.P.","relationship":{"ten_percent_owner":true}},{"id":149132,"kind":"organization","name":"MGC Venture Partners 2018 GP, LLC","position":3,"cik":"0001783291","reported_name":"MGC Venture Partners 2018 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149133,"kind":"organization","name":"MGC VENTURE PARTNERS 2018, L.P.","position":4,"cik":"0001745133","reported_name":"MGC VENTURE PARTNERS 2018, L.P.","relationship":{"ten_percent_owner":true}},{"id":149134,"kind":"organization","name":"MGC VENTURE PARTNERS QP 2018, L.P.","position":5,"cik":"0001749814","reported_name":"MGC VENTURE PARTNERS QP 2018, L.P.","relationship":{"ten_percent_owner":true}}],"security":"Series A Preferred Stock","published_at":"2019-07-31T17:57:31.000Z","date":"2019-07-29","kind":"exercise","acquired":false,"shares":19524,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"derivative.exercise_price","element":"conversionOrExercisePrice","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"derivative.expiration_date","element":"expirationDate","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Held directly by MGC 2013 LP."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"MGC Venture Partners 2013 GP, LLC (\"MGC 2013 GP\") is the general partner of MGC 2013 LP. MGC Venture Partners 2018 GP, LLC (\"MGC 2018 GP\") is the general partner of MGC Venture Partners 2018, L.P. (\"MGC 2018 LP\") and MGC Venture Partners QP 2018, L.P. (\"MGC QP 2018 LP\"). Each of MGC 2013 LP, MGC 2013 GP, MGC 2018 LP, MGC QP 2018 LP and MGC 2018 GP directly (whether through ownership or position) or indirectly through one or more intermediaries, may be deemed for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, to be the indirect beneficial owner of some or all of the shares owned by MGC 2013 LP, MGC 2018 LP and MGC QP 2018 LP and, therefore, a \"ten percent holder\" hereunder."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F5","text":"Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton and Byron W. Smith are managing directors of MGC 2013 GP and share voting and investment power over the shares held by MGC 2013 LP. Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton, Byron W. Smith, Jay Ferguson and Rob Readnour are managing partners of MGC 2018 GP and share voting and investment power over the shares held by MGC 2018 LP and MGC QP 2018 LP. Each of the Reporting Persons disclaims beneficial ownership of the shares held by any other Reporting Persons reported herein, except to the extent of its pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Persons are the beneficial owners of such securities for purposes of Section 16 or for any other purposes."}],"balance_after":0,"derivative":{"underlying":"CommonStock","underlying_shares":16015},"source":{"system":"sec-edgar","filing":"0001140361-19-013900","document":"form4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":6,"url":"https://www.sec.gov/Archives/edgar/data/1783291/000114036119013900/form4.xml","form_type":"4"}},{"id":3452759,"issuer":{"id":359,"kind":"organization","name":"CASTLE BIOSCIENCES INC","symbol":"CSTL"},"owners":[{"id":149130,"kind":"organization","name":"MGC Venture Partners 2013 GP, LLC","position":1,"cik":"0001783292","reported_name":"MGC Venture Partners 2013 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149131,"kind":"organization","name":"MGC Venture Partners 2013, L.P.","position":2,"cik":"0001572764","reported_name":"MGC Venture Partners 2013, L.P.","relationship":{"ten_percent_owner":true}},{"id":149132,"kind":"organization","name":"MGC Venture Partners 2018 GP, LLC","position":3,"cik":"0001783291","reported_name":"MGC Venture Partners 2018 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149133,"kind":"organization","name":"MGC VENTURE PARTNERS 2018, L.P.","position":4,"cik":"0001745133","reported_name":"MGC VENTURE PARTNERS 2018, L.P.","relationship":{"ten_percent_owner":true}},{"id":149134,"kind":"organization","name":"MGC VENTURE PARTNERS QP 2018, L.P.","position":5,"cik":"0001749814","reported_name":"MGC VENTURE PARTNERS QP 2018, L.P.","relationship":{"ten_percent_owner":true}}],"security":"Common Stock","published_at":"2019-07-31T17:57:31.000Z","date":"2019-07-29","kind":"purchase","acquired":true,"shares":134700,"price":16,"value":2155200.0,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"shares","element":"transactionShares","label":"F7","text":"Represents a purchase from the underwriters in the Issuer's IPO."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"MGC Venture Partners 2013 GP, LLC (\"MGC 2013 GP\") is the general partner of MGC 2013 LP. MGC Venture Partners 2018 GP, LLC (\"MGC 2018 GP\") is the general partner of MGC Venture Partners 2018, L.P. (\"MGC 2018 LP\") and MGC Venture Partners QP 2018, L.P. (\"MGC QP 2018 LP\"). Each of MGC 2013 LP, MGC 2013 GP, MGC 2018 LP, MGC QP 2018 LP and MGC 2018 GP directly (whether through ownership or position) or indirectly through one or more intermediaries, may be deemed for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, to be the indirect beneficial owner of some or all of the shares owned by MGC 2013 LP, MGC 2018 LP and MGC QP 2018 LP and, therefore, a \"ten percent holder\" hereunder."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F5","text":"Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton and Byron W. Smith are managing directors of MGC 2013 GP and share voting and investment power over the shares held by MGC 2013 LP. Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton, Byron W. Smith, Jay Ferguson and Rob Readnour are managing partners of MGC 2018 GP and share voting and investment power over the shares held by MGC 2018 LP and MGC QP 2018 LP. Each of the Reporting Persons disclaims beneficial ownership of the shares held by any other Reporting Persons reported herein, except to the extent of its pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Persons are the beneficial owners of such securities for purposes of Section 16 or for any other purposes."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F9","text":"Held directly by MGC QP 2018 LP."}],"balance_after":134700,"source":{"system":"sec-edgar","filing":"0001140361-19-013900","document":"form4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":5,"url":"https://www.sec.gov/Archives/edgar/data/1783291/000114036119013900/form4.xml","form_type":"4"}},{"id":3452758,"issuer":{"id":359,"kind":"organization","name":"CASTLE BIOSCIENCES INC","symbol":"CSTL"},"owners":[{"id":149130,"kind":"organization","name":"MGC Venture Partners 2013 GP, LLC","position":1,"cik":"0001783292","reported_name":"MGC Venture Partners 2013 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149131,"kind":"organization","name":"MGC Venture Partners 2013, L.P.","position":2,"cik":"0001572764","reported_name":"MGC Venture Partners 2013, L.P.","relationship":{"ten_percent_owner":true}},{"id":149132,"kind":"organization","name":"MGC Venture Partners 2018 GP, LLC","position":3,"cik":"0001783291","reported_name":"MGC Venture Partners 2018 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149133,"kind":"organization","name":"MGC VENTURE PARTNERS 2018, L.P.","position":4,"cik":"0001745133","reported_name":"MGC VENTURE PARTNERS 2018, L.P.","relationship":{"ten_percent_owner":true}},{"id":149134,"kind":"organization","name":"MGC VENTURE PARTNERS QP 2018, L.P.","position":5,"cik":"0001749814","reported_name":"MGC VENTURE PARTNERS QP 2018, L.P.","relationship":{"ten_percent_owner":true}}],"security":"Common Stock","published_at":"2019-07-31T17:57:31.000Z","date":"2019-07-29","kind":"purchase","acquired":true,"shares":115300,"price":16,"value":1844800.0,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"shares","element":"transactionShares","label":"F7","text":"Represents a purchase from the underwriters in the Issuer's IPO."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"MGC Venture Partners 2013 GP, LLC (\"MGC 2013 GP\") is the general partner of MGC 2013 LP. MGC Venture Partners 2018 GP, LLC (\"MGC 2018 GP\") is the general partner of MGC Venture Partners 2018, L.P. (\"MGC 2018 LP\") and MGC Venture Partners QP 2018, L.P. (\"MGC QP 2018 LP\"). Each of MGC 2013 LP, MGC 2013 GP, MGC 2018 LP, MGC QP 2018 LP and MGC 2018 GP directly (whether through ownership or position) or indirectly through one or more intermediaries, may be deemed for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, to be the indirect beneficial owner of some or all of the shares owned by MGC 2013 LP, MGC 2018 LP and MGC QP 2018 LP and, therefore, a \"ten percent holder\" hereunder."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F5","text":"Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton and Byron W. Smith are managing directors of MGC 2013 GP and share voting and investment power over the shares held by MGC 2013 LP. Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton, Byron W. Smith, Jay Ferguson and Rob Readnour are managing partners of MGC 2018 GP and share voting and investment power over the shares held by MGC 2018 LP and MGC QP 2018 LP. Each of the Reporting Persons disclaims beneficial ownership of the shares held by any other Reporting Persons reported herein, except to the extent of its pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Persons are the beneficial owners of such securities for purposes of Section 16 or for any other purposes."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F8","text":"Held directly by MGC 2018 LP."}],"balance_after":115300,"source":{"system":"sec-edgar","filing":"0001140361-19-013900","document":"form4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1783291/000114036119013900/form4.xml","form_type":"4"}},{"id":3452757,"issuer":{"id":359,"kind":"organization","name":"CASTLE BIOSCIENCES INC","symbol":"CSTL"},"owners":[{"id":149130,"kind":"organization","name":"MGC Venture Partners 2013 GP, LLC","position":1,"cik":"0001783292","reported_name":"MGC Venture Partners 2013 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149131,"kind":"organization","name":"MGC Venture Partners 2013, L.P.","position":2,"cik":"0001572764","reported_name":"MGC Venture Partners 2013, L.P.","relationship":{"ten_percent_owner":true}},{"id":149132,"kind":"organization","name":"MGC Venture Partners 2018 GP, LLC","position":3,"cik":"0001783291","reported_name":"MGC Venture Partners 2018 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149133,"kind":"organization","name":"MGC VENTURE PARTNERS 2018, L.P.","position":4,"cik":"0001745133","reported_name":"MGC VENTURE PARTNERS 2018, L.P.","relationship":{"ten_percent_owner":true}},{"id":149134,"kind":"organization","name":"MGC VENTURE PARTNERS QP 2018, L.P.","position":5,"cik":"0001749814","reported_name":"MGC VENTURE PARTNERS QP 2018, L.P.","relationship":{"ten_percent_owner":true}}],"security":"Common Stock","published_at":"2019-07-31T17:57:31.000Z","date":"2019-07-29","kind":"purchase","acquired":true,"shares":62500,"price":16,"value":1000000.0,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"shares","element":"transactionShares","label":"F7","text":"Represents a purchase from the underwriters in the Issuer's IPO."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Held directly by MGC 2013 LP."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"MGC Venture Partners 2013 GP, LLC (\"MGC 2013 GP\") is the general partner of MGC 2013 LP. MGC Venture Partners 2018 GP, LLC (\"MGC 2018 GP\") is the general partner of MGC Venture Partners 2018, L.P. (\"MGC 2018 LP\") and MGC Venture Partners QP 2018, L.P. (\"MGC QP 2018 LP\"). Each of MGC 2013 LP, MGC 2013 GP, MGC 2018 LP, MGC QP 2018 LP and MGC 2018 GP directly (whether through ownership or position) or indirectly through one or more intermediaries, may be deemed for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, to be the indirect beneficial owner of some or all of the shares owned by MGC 2013 LP, MGC 2018 LP and MGC QP 2018 LP and, therefore, a \"ten percent holder\" hereunder."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F5","text":"Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton and Byron W. Smith are managing directors of MGC 2013 GP and share voting and investment power over the shares held by MGC 2013 LP. Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton, Byron W. Smith, Jay Ferguson and Rob Readnour are managing partners of MGC 2018 GP and share voting and investment power over the shares held by MGC 2018 LP and MGC QP 2018 LP. Each of the Reporting Persons disclaims beneficial ownership of the shares held by any other Reporting Persons reported herein, except to the extent of its pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Persons are the beneficial owners of such securities for purposes of Section 16 or for any other purposes."}],"balance_after":1496855,"source":{"system":"sec-edgar","filing":"0001140361-19-013900","document":"form4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1783291/000114036119013900/form4.xml","form_type":"4"}},{"id":3452756,"issuer":{"id":359,"kind":"organization","name":"CASTLE BIOSCIENCES INC","symbol":"CSTL"},"owners":[{"id":149130,"kind":"organization","name":"MGC Venture Partners 2013 GP, LLC","position":1,"cik":"0001783292","reported_name":"MGC Venture Partners 2013 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149131,"kind":"organization","name":"MGC Venture Partners 2013, L.P.","position":2,"cik":"0001572764","reported_name":"MGC Venture Partners 2013, L.P.","relationship":{"ten_percent_owner":true}},{"id":149132,"kind":"organization","name":"MGC Venture Partners 2018 GP, LLC","position":3,"cik":"0001783291","reported_name":"MGC Venture Partners 2018 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149133,"kind":"organization","name":"MGC VENTURE PARTNERS 2018, L.P.","position":4,"cik":"0001745133","reported_name":"MGC VENTURE PARTNERS 2018, L.P.","relationship":{"ten_percent_owner":true}},{"id":149134,"kind":"organization","name":"MGC VENTURE PARTNERS QP 2018, L.P.","position":5,"cik":"0001749814","reported_name":"MGC VENTURE PARTNERS QP 2018, L.P.","relationship":{"ten_percent_owner":true}}],"security":"Common Stock","published_at":"2019-07-31T17:57:31.000Z","date":"2019-07-29","kind":"exercise","acquired":true,"shares":97428,"price":12.8,"value":1247078.4,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F6","text":"The principal amount of the Convertible Promissory Note held by the designated Reporting Person was $1,200,000.00. Upon closing of the IPO, all unpaid principal and accrued interest outstanding on the Convertible Promissory Note (the \"Conversion Amount\") automatically converted into the number of shares of Common Stock equal to the Conversion Amount as of the date immediately prior to the closing date divided by 80% of the IPO price per share of $16.00 per share."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Held directly by MGC 2013 LP."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"MGC Venture Partners 2013 GP, LLC (\"MGC 2013 GP\") is the general partner of MGC 2013 LP. MGC Venture Partners 2018 GP, LLC (\"MGC 2018 GP\") is the general partner of MGC Venture Partners 2018, L.P. (\"MGC 2018 LP\") and MGC Venture Partners QP 2018, L.P. (\"MGC QP 2018 LP\"). Each of MGC 2013 LP, MGC 2013 GP, MGC 2018 LP, MGC QP 2018 LP and MGC 2018 GP directly (whether through ownership or position) or indirectly through one or more intermediaries, may be deemed for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, to be the indirect beneficial owner of some or all of the shares owned by MGC 2013 LP, MGC 2018 LP and MGC QP 2018 LP and, therefore, a \"ten percent holder\" hereunder."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F5","text":"Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton and Byron W. Smith are managing directors of MGC 2013 GP and share voting and investment power over the shares held by MGC 2013 LP. Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton, Byron W. Smith, Jay Ferguson and Rob Readnour are managing partners of MGC 2018 GP and share voting and investment power over the shares held by MGC 2018 LP and MGC QP 2018 LP. Each of the Reporting Persons disclaims beneficial ownership of the shares held by any other Reporting Persons reported herein, except to the extent of its pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Persons are the beneficial owners of such securities for purposes of Section 16 or for any other purposes."}],"balance_after":1434355,"source":{"system":"sec-edgar","filing":"0001140361-19-013900","document":"form4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1783291/000114036119013900/form4.xml","form_type":"4"}},{"id":3452755,"issuer":{"id":359,"kind":"organization","name":"CASTLE BIOSCIENCES INC","symbol":"CSTL"},"owners":[{"id":149130,"kind":"organization","name":"MGC Venture Partners 2013 GP, LLC","position":1,"cik":"0001783292","reported_name":"MGC Venture Partners 2013 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149131,"kind":"organization","name":"MGC Venture Partners 2013, L.P.","position":2,"cik":"0001572764","reported_name":"MGC Venture Partners 2013, L.P.","relationship":{"ten_percent_owner":true}},{"id":149132,"kind":"organization","name":"MGC Venture Partners 2018 GP, LLC","position":3,"cik":"0001783291","reported_name":"MGC Venture Partners 2018 GP, LLC","relationship":{"ten_percent_owner":true}},{"id":149133,"kind":"organization","name":"MGC VENTURE PARTNERS 2018, L.P.","position":4,"cik":"0001745133","reported_name":"MGC VENTURE PARTNERS 2018, L.P.","relationship":{"ten_percent_owner":true}},{"id":149134,"kind":"organization","name":"MGC VENTURE PARTNERS QP 2018, L.P.","position":5,"cik":"0001749814","reported_name":"MGC VENTURE PARTNERS QP 2018, L.P.","relationship":{"ten_percent_owner":true}}],"security":"Common Stock","published_at":"2019-07-31T17:57:31.000Z","date":"2019-07-29","kind":"exercise","acquired":true,"shares":1336927,"ownership":{"direct":false,"nature":"See footnotes"},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"The shares of Common Stock issued upon conversion of the Preferred Stock were calculated by first aggregating all series of Preferred Stock held by MGC Venture Partners 2013, L.P. (\"MGC 2013 LP\"), in accordance with the terms of the then-effective Certificate of Incorporation of Castle Biosciences, Inc. (the \"Issuer\")."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Every 1.219 outstanding shares of Preferred Stock automatically converted into 1 share of Common Stock immediately prior to the closing of the Issuer's initial public offering (the \"IPO\"), for no additional consideration, with cash paid for any fractional shares. The Preferred Stock had no expiration date."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F3","text":"Held directly by MGC 2013 LP."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F4","text":"MGC Venture Partners 2013 GP, LLC (\"MGC 2013 GP\") is the general partner of MGC 2013 LP. MGC Venture Partners 2018 GP, LLC (\"MGC 2018 GP\") is the general partner of MGC Venture Partners 2018, L.P. (\"MGC 2018 LP\") and MGC Venture Partners QP 2018, L.P. (\"MGC QP 2018 LP\"). Each of MGC 2013 LP, MGC 2013 GP, MGC 2018 LP, MGC QP 2018 LP and MGC 2018 GP directly (whether through ownership or position) or indirectly through one or more intermediaries, may be deemed for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, to be the indirect beneficial owner of some or all of the shares owned by MGC 2013 LP, MGC 2018 LP and MGC QP 2018 LP and, therefore, a \"ten percent holder\" hereunder."},{"field":"ownership.nature","element":"natureOfOwnership","label":"F5","text":"Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton and Byron W. Smith are managing directors of MGC 2013 GP and share voting and investment power over the shares held by MGC 2013 LP. Each of Joseph C. Cook, Jr., Joseph C. Cook III, Steven D. Singleton, Byron W. Smith, Jay Ferguson and Rob Readnour are managing partners of MGC 2018 GP and share voting and investment power over the shares held by MGC 2018 LP and MGC QP 2018 LP. Each of the Reporting Persons disclaims beneficial ownership of the shares held by any other Reporting Persons reported herein, except to the extent of its pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Persons are the beneficial owners of such securities for purposes of Section 16 or for any other purposes."}],"balance_after":1336927,"source":{"system":"sec-edgar","filing":"0001140361-19-013900","document":"form4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1783291/000114036119013900/form4.xml","form_type":"4"}}]}