144 0001236397 XXXXXXXX LIVE 0001447362 Castle Biosciences, Inc. 001-38984 505 S. Friendswood Drive Suite 401 Friendswood TX 77546 1-866-788-9007 Daniel Bradbury Officer Common Goldman Sachs & Co. LLC 200 West Street New York NY 10282 7867 221220.04 28007301 02/05/2025 NASD Common 12/08/2020 Acquired as a gift Daniel M. Bradbury Y 09/12/2008 1425 12/08/2020 N/A Common 12/08/2020 Acquired as a gift Daniel M. Bradbury Y 09/12/2008 1425 12/08/2020 N/A Common 06/08/2018 Acquired from issuer in private transaction Issuer N 5017 06/08/2018 N/A N The Daniel M. Bradbury Irrevocable Descendants Trust 505 S. Friendswood Drive Suite 401 Friendswood TX 77546 Common 01/06/2025 1425 41524.36 The Annette E. Bradbury Irrevocable Descendants Trust 505 S. Friendswood Drive Suite 401 Friendswood TX 77546 Common 01/06/2025 1425 41524.36 BioBrit, LLC 505 S. Friendswood Drive Suite 401 Friendswood TX 77546 Common 01/06/2025 5017 146194.88 The Daniel M. Bradbury Irrevocable Descendants Trust 505 S. Friendswood Drive Suite 401 Friendswood TX 77546 Common 12/03/2024 1425 44142.08 The Annette E. Bradbury Irrevocable Descendants Trust 505 S. Friendswood Drive Suite 401 Friendswood TX 77546 Common 12/03/2024 1425 44142.08 BioBrit, LLC 505 S. Friendswood Drive Suite 401 Friendswood TX 77546 Common 12/03/2024 5017 155411.11 Total number of shares to be sold includes 5,017 shares by BioBrit, LLC, 1,425 shares by The Daniel M. Bradbury Irrevocable Descendants Trust, 1,425 shares by The Annette E. Bradbury Irrevocable Descendants Trust. The sales set forth herein are made in connection with a selling plan dated 5/10/2024, that is intended to comply with Rule 105-1 (c). 02/05/2025 05/10/2024 Goldman Sachs & Co. LLC on behalf of Daniel M. Bradbury