CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER
I, Jonathan Lewis, certify that:
| 1. | I have reviewed this amendment to the annual report on Form 10-K/A of ZIOPHARM Oncology, Inc.; 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: April 30, 2010
| | | | | |
| /s/ Jonathan Lewis | | | | |
Jonathan Lewis, Chief Executive Officer | | | | |
(Principal Executive Officer) | | | | |
