GIP (rat) (Glucose-dependent Insulinotropic Polypeptide), also known as Gastric Inhibitory Polypeptide, is a biologically active 42-amino acid peptide secreted by the K cells of the duodenum and jejunum following food consumption. It belongs to the incretin hormone peptide family, which includes GLP (Gastric-like Peptide), and it not only stimulates insulin release from pancreatic islet β-cells but also may encourage β-cell proliferation and survival. Additionally, recent research indicates GIP may have a role in lipid regulation and could contribute to the development of obesity.