ANGPTL8 (also known as lipasin, originally Betatrophin) is a protein that in humans is encoded by the C19orf80 gene. The gene for betatrophin lies on mouse chromosome 9 (gene symbol: Gm6484) and on human chromosome 19 (gene symbol: C19orf80). The encoded 22 kDa protein contains an N-terminal secretion signal and two coiled-coil domains and is a member of the angiopoietin-like (ANGPTL) protein family. However, in contrast to other ANGPTL proteins, betatrophin lacks the C-terminal fibrinogen-like domain, and therefore it is an atypical member of the ANGPTL family. It shares with Angptl4 and Angptl3 the ability to inhibit the enzyme Lipoprotein lipase (LPL), and its hepatic overexpression causes elevation of circulating Triglyceride levels in mice. In mice betatrophin is secreted by the liver. It was hoped that betatrophin or its homolog in humans may provide an effective treatment for type 2 diabetes and perhaps even type I diabetes.