144 0001856542 XXXXXXXX LIVE 0001447362 CASTLE BIOSCIENCES INC 001-38984 505 S. Friendswood Drive, Suite 401 Friendstown TX 77546 8667889007 TOBIN JUVENAL Officer Common Morgan Stanley Smith Barney LLC Executive Financial Services

1 New York Plaza 8th Floor New York NY 10004

5393 187352.82 29188659 11/11/2025 NASDAQ Common 11/11/2025 Exercise of Stock Options Issuer N 5393 11/11/2025 Cash Y The securities to be sold were and will be received upon the exercise of stock options over the next three months. The dates of acquisition and payment were and will be the dates of exercise/sale. Sales that were executed on November 11, 2025 are being reported on this Form 144 filed on November 12, 2025 given the EDGAR system was not accepting filings on November 11, 2025 in observance of the federal holiday. 11/11/2025 09/11/2024 /s/ Tobin Juvenal