AMGen (formerly Applied Molecular Genetics Inc.) is an American multinational biopharmaceutical company headquartered in Thousand Oaks, California. Located in the Conejo Valley, AMGen is the world's largest independent biotechnology firm. In 2013, the company's largest selling product lines were Neulasta/Neupogen, two closely related drugs used to prevent infections in patients undergoing cancer chemotherapy; and Enbrel, a tumor necrosis factor blocker used in the treatment of rheumatoid arthritis and other autoimmune diseases. Other products include Epogen, Aranesp, Sensipar/Mimpara, Nplate, Vectibix, Prolia and XGEVA.