Gilead Sciences, Inc. () is an American biopharmaceutical company headquartered in Foster City, California, that focuses on researching and developing antiviral drugs used in the treatment of HIV/AIDS, hepatitis B, hepatitis C, influenza, and COVID-19, including ledipasvir/sofosbuvir and sofosbuvir. Gilead is a member of the NASDAQ Biotechnology Index and the S&P 500. Gilead was founded in 1987 under the name Oligogen by Michael L. Riordan. The original name was a reference to oligomers, small strands of DNA used to target genetic sequences. Gilead held its IPO in 1992, and successfully developed drugs like Tamiflu and Vistide that decade. In the 2000s, Gilead received approval for drugs including Viread and Hepsera, among others. It began evolving from a biotechnology company into a pharmaceutical company, acquiring several subsidiaries, though it still relied heavily on contracting to manufacture its drugs. The company continued its growth in the 2010s, but came under heavy scrutiny over its business practices, including extremely high pricing of drugs such as Sovaldi and Truvada in the United States relative to production cost and cost in the developing world. History Foundation In June 1987, Gilead Sciences was originally founded under the name Oligogen by Michael L. Riordan, a medical doctor. Riordan graduated from Washington University in St. Louis, the Johns Hopkins School of Medicine, and the Harvard Business School. The ideation began as a research project at Menlo Ventures where Michael was an associate. Three scientific advisers worked with Riordan to create the company: Peter Dervan of Caltech, Doug Melton of Harvard, and Harold M. Weintraub of the Fred Hutchinson Cancer Research Center, along with H. Dubose Montgomery, one of Menlo Ventures founders. Riordan served as CEO from the company's founding until 1996. Menlo Ventures subsequently made the first investment in Gilead of $2 million. Riordan also recruited scientific advisers including Harold Varmus, a Nobel laureate who later became Director of the National Institutes of Health, and Jack Szostak, recipient of the Nobel Prize for Physiology or Medicine in 2009. The company's primary therapeutic focus was in antiviral medicines, a field that piqued Riordan's interest after he contracted dengue fever. Riordan recruited Donald Rumsfeld to join the board of directors in 1988, followed by Benno C. Schmidt, Sr., Gordon Moore, and George P. Shultz. Riordan tried to recruit Warren Buffett as an investor and board member, but was unsuccessful. The company focused its early research on making small strands of