On December 17, 2020, the board of directors of Keros Therapeutics, Inc., based upon a recommendation from the Nominating and Corporate Governance Committee of the Board, voted to appoint Dr. Mary Ann Gray as a director of the Company, effective immediately. Dr. Gray was appointed as a Class II director with a term expiring at the Company’s 2022 annual meeting of stockholders. The Board also appointed Dr. Gray to serve as the chair of the Audit Committee of the Board and as a member of the Compensation Committee. In addition, on December 14, 2020, Dr. Alon Lazarus submitted his resignation from the Board, including from the Board's Audit and Compensation Committees, effective December 17, 2020. Dr. Lazarus’ resignation was not the result of any disagreement with the Company on any matter relating to the Company’s operations, policies or practices.