Islet Neogenesis-Associated Protein (INGAP) is a member of the Reg family of proteins implicated in various settings of endogenous pancreatic regeneration. The expression of INGAP and other RegIII proteins has also been linked temporally and spatially with the induction of islet neogenesis in animal models of disease and regeneration. Furthermore, administration of a peptide fragment of INGAP (INGAP peptide) has been demonstrated to reverse chemically induced diabetes as well as improve glycemic control and survival in an animal model of type 1 diabetes. Cultured human pancreatic tissue has also been shown to be responsive to INGAP peptide, producing islet-like structures with function, architecture and gene expression matching that of freshly isolated islets. Likewise, studies in normoglycemic animals show evidence of islet neogenesis. Finally, recent clinical studies suggest an effect of INGAP peptide to improve insulin production in type 1 diabetes and glycemic control in type 2 diabetes.