Regenerating protein 2 (Reg2) also known as Lithostathine 2, pancreatic thread protein (PTP2) and pancreatic stone protein 2 (PSP2), is a member of the Reg family of proteins. These small, secreted proteins have been implicated in a range of physiological processes including acting as acute phase reactants, lectins, survival/growth factors for insulin-producing pancreatic beta-cells, neural cells, and epithelial cells of the digestive system. Studies also indicate a role for Reg family members in tumor formation and indicate their potential for use as biomarkers of carcinogenesis. Mouse Reg2 is expressed in regenerating islets and normal exocrine pancreas. Reg2 also stimulates the growth of pancreatic beta cells. Mouse Reg2 belongs to the type II subclass of the Reg family and is the only subclass II Reg protein described.