Gilead Sciences, Inc., a research-based biopharmaceutical company, discovers, develops, and commercializes medicines in the areas of unmet medical needs in Europe, North America, Asia, South America, Africa, Australia, India, and the Middle East. The company's products include Descovy, Odefsey, Genvoya, Stribild, Complera/Eviplera, Atripla, Truvada, Viread, Emtriva, Tybost, and Vitekta for the treatment of human immunodeficiency virus (HIV) infection in adults; and Vemlidy, Epclusa, Harvoni, Sovaldi, Viread, and Hepsera products for treating liver diseases. It also offers Zydelig, a PI3K delta inhibitor, in combination with rituximab, for the treatment of certain blood cancers; Letairis, an endothelin receptor antagonist for the treatment of pulmonary arterial hypertension; Ranexa, a tablet used for the treatment of chronic angina; Lexiscan/Rapiscan injection for use as a pharmacologic stress agent in radionuclide myocardial perfusion imaging; Cayston, an inhaled antibiotic for the treatment of respiratory systems in cystic fibrosis patients; and Tamiflu, an oral antiviral capsule for the treatment and prevention of influenza A and B. In addition, the company provides other products, such as AmBisome, an antifungal agent to treat serious invasive fungal infections; and Macugen, an anti-angiogenic oligonucleotide to treat neovascular age-related macular degeneration. Further, it has product candidates in various stages of development for the treatment of HIV/AIDS and liver diseases, such as hepatitis C virus and hepatitis B virus; hematology/oncology; cardiovascular; and inflammation/respiratory diseases. The company markets its products through its commercial teams and/or in conjunction with third-party distributors and corporate partners. Gilead Sciences, Inc. has collaboration agreements with Bristol-Myers Squibb Company, Janssen R&D Ireland, Japan Tobacco Inc., and Galapagos NV. The company was founded in 1987 and is headquartered in Foster City, California.