GPR40 (FFAR1) is a member of the G protein-coupled receptor family, characterized by seven transmembrane domains. It is primarily expressed in pancreatic beta cells and intestinal epithelial cells, and is involved in regulating insulin secretion and energy metabolism. GPR40 activates signaling pathways by recognizing long-chain unsaturated fatty acids, enhancing insulin release, and regulating blood sugar levels. Mutations or aberrant expression of GPR40 are associated with the development of diabetes.