Power of Attorney for Timothy Williams

This filing contains a Power of Attorney document appointing Michelle Robertson, Ankita Patel, Agnieszka Cieplinska, and Katie Harmon as attorneys-in-fact for Timothy Williams. They are authorized to execute and submit SEC Forms 3, 4, and 5, including amendments, on behalf of Mr. Williams, who is an officer of Geron Corporation. This authorization covers all necessary actions for timely filing with the SEC and other relevant authorities. The Power of Attorney remains effective until Mr. Williams is no longer required to file these forms, revokes it in writing, or the appointed attorneys-in-fact are no longer employed by the Company. The document was signed by Timothy Williams on April 9, 2026.