On September 29, 2021, Dr. Richard Klausner, the Chair of the Board of Directors (the “Board”) of Lyell Immunopharma, Inc. (the “Company”) informed the Company that (a) he will take a temporary medical leave of absence and is expected to return in early 2022 (the “Leave”) and (b) he will also be resigning from his position as Executive Chairman of the Company and will no longer be an employee, effective October 1, 2022. However, Dr. Klausner will remain Chair of the Board. The Board has elected Cathy Friedman, its lead independent director, to serve as the interim Chair of the Board during Dr. Klausner’s absence. The Board and the Company’s employees wish Dr. Klausner a quick and full recovery and look forward to his return to the role of Chair following the Leave.