At a meeting held on January 28, 2020, the Board of Directors of Gilead Sciences, Inc. elected Dr. Sandra J. Horning to serve on the Board, effective immediately. Dr. Horning was also appointed as a member of the Nominating and Corporate Governance Committee and the Scientific Committee of the Board. On January 29, 2020, the company designated Diane E. Wilfong, Senior Vice President, Corporate Controller and Chief Accounting Officer, as the principal accounting officer for purposes of the company's filings with the SEC, effective immediately.