Instil Bio, Inc.

Director and Officer Trading Arrangements

None of our directors or executive officers adopted orterminated a Rule 10b5-1 trading arrangement or a non-Rule 10b5-1 trading arrangement (as defined in Item 408(c) of Regulation S-K) during the quarterly period covered by this report.

Second Amended and Restated Executive Employment Agreement with Sandeep Laumas, M.D.

On May 12, 2025, the Company and Sandeep Laumas, the Company’s Chief Financial Officer and Chief Business Officer, or Executive, entered into a Second Amended and Restated Executive Employment Agreement, or Amended Employment Agreement. The Amended Employment Agreement amends the Amended and Restated Executive Employment Agreement between the Company and Executive dated June 30, 2020, or the Prior Agreement, to provide that 100% of Executive’s then unvested shares subject to all stock options shall vest immediately prior to the closing of a Change in Control (as defined in the 2021 Plan), subject to Executive’s continuous service with the Company through such date. The Amended Employment Agreement also includes administrative amendments to the Prior Agreement to, among other things, reflect Dr. Laumas’ current title and base salary of $528,943. The foregoing description of the Amended Employment Agreement and the changes made to the Prior Agreement do not purport to be complete and are subject to, and qualified in its entirety by, the full text of the Amended Employment Agreement, a copy of which is filed as Exhibit 10.1 hereto and is incorporated by reference herein.