Castle Biosciences stockholders elect three Class I directors and ratify KPMG as auditor at 2026 annual meeting

Proposal 1. Election of Directors The Company’s stockholders elected the three individuals listed below as Class I Directors, each to serve until the Company’s 2029 annual meeting of stockholders and until their successors are duly elected and qualified. The final voting results are as follows: For Withhold Broker Non-Votes Ellen Goldberg 15,455,265 7,118,166 2,415,788 Miles D. Harrison 15,607,369 6,966,062 2,415,788 Tiffany P. Olson 14,380,655 8,192,776 2,415,788

Proposal 2. Ratification of the Selection of Independent Registered Public Accounting Firm The Company’s stockholders ratified the selection of KPMG LLP by the Audit Committee of the Company’s Board of Directors as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2026. The final voting results are as follows: For Against Abstain 24,531,366 445,666 12,187

Proposal 3. Approval of the Compensation of the Company’s Named Executive Officers The Company’s stockholders approved, on an advisory basis, the compensation of the Company’s named executive officers as disclosed in the Company’s definitive proxy statement on Schedule 14A, filed with the Securities and Exchange Commission on April 8, 2026 (the “Proxy Statement”). The final voting results are as follows: For Against Abstain Broker Non-Votes 21,280,180 1,281,394 11,857 2,415,788

Proposal 4. Approval of the Company’s Non-Employee Director Compensation Policy The Company’s stockholders approved the Company’s non-employee director compensation policy as described in the Proxy Statement. The final voting results are as follows: For Against Abstain Broker Non-Votes 21,394,330 1,130,133 48,968 2,415,788