Gilead Sciences is a biopharmaceutical company that discovers, develops, and commercializes innovative medicines for life-threatening diseases including HIV, viral hepatitis, cancer, and other serious conditions across virology, oncology, and related therapeutic areas. The company's revenue comes primarily from global product sales of over 25 therapies—including antiretroviral regimens, hepatitis treatments, CAR T-cell therapies, antibody-drug conjugates, and antiviral or antifungal medications—distributed through major wholesalers and specialty channels in the United States and through commercial teams and partners in international markets. Gilead operates in a highly competitive landscape and invests significantly in research and development to expand its pipeline and maintain competitive advantages in efficacy, safety, pricing, and insurance coverage.