EXHIBIT 31.3
CERTIFICATION PURSUANT TO
FORM OF RULE 13A-14(A)
AS ADOPTED PURSUANT TO
SECTION 302(A) OF THE SARBANES-OXLEY ACT OF 2002
I, John A. Scarlett, M.D., President and Chief Executive Officer of Geron Corporation, certify that:
| 1. | I have reviewed this Amendment No. 1 to the Annual Report on Form 10-K/A of Geron Corporation; and | ||
| 2. | Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report. | ||
| Date: March 27, 2012 | |
| /s/ JOHN A. SCARLETT | |
| John A. Scarlett, M.D. | |
| President and Chief Executive Officer | |
