Human gastric inhibitory polypeptide (GIP) is a 42-amino-acid peptide belonging to the glucagon-secretin family of peptide hormones. It is secreted by endocrine cells in the duodenal mucosa and stimulates glucose-dependent insulin secretion as well as GLP-1 release from more distal endocrine (L) cells in the intestinal mucosa. GIP shows amino-acid sequence similarities to glucagon, GLP-1 and GLP-2 (from approximately 50% identity for glucagon to 30% identity for GLP-2). This antibody binds human GIP but does not cross-react with GLP-1 or -2, PACAP, glucagon or VIP. Cross-reactivity with porcine GIP has not been determined.