Anti-GIP antibodies are used in the immunodetection of the protein gastric inhibitory polypeptide. In humans, the canonical protein has a reported length of 153 amino acid residues and a mass of 17.1 kDa. It is known to be a secreted protein. A member of a the Glucagon protein family, GIP is reported to be a potent stimulator of insulin secretion and relatively poor inhibitor of gastric acid secretion. Synonyms for this target antigen include glucose-dependent insulinotropic polypeptide and incretin hormone.