Additional Relevant Details John Martin joined Gilead in 1990 and was appointed Chief Executive Officer in 1996 and Chairman of the Board in 2008. John Milligan also joined Gilead in 1990 and was appointed Chief Operating Officer in 2007 and President in 2008.“John Martin has led Gilead as CEO for the past 20 years, and under his stewardship, the company has developed and delivered therapeutic advancements to millions of people around the world. His legacy is clear – and the vision he has set will continue with his contributions as Executive Chairman,” said John Cogan, PhD, Gilead’s Lead Independent Director.