Clusterin is a highly glycosylated heterodimeric glycoprotein that plays diverse biological roles in various organs. The secreted clusterin has been established as a major form of the protein that exerts diverse tissue effects. For instance, clusterin is known to act in cell protection through the actions of extra-cellular molecular chaperones. In the extracellular milieu, clusterin participates in specific interactions with a diverse array of native biological molecules including LRP-2 (Lipoprotein receptor-related protein 2, also known as gp330 or megalin), which is involved in ligand endocytosis at the surfaces of certain epithelia. Clusterin is expressed transiently in developing and differentiating endocrine pancreatic cells and might be involved in pancreas development. This transient expression of clusterin at specific time points of pancreas development and cell differentiation during pancreas regeneration implies that the protein is a regulatory factor for cytodifferentiation as well as for replication. A specific action of the clusterin in the reconstruction and remodeling of the endocrine pancreas has been demonstrated. It also strongly stimulates duct cell differentiation into insulin-secreting cells under in vitro culture conditions. Clusterin appears thus as a potent regulator of insulin cell morphogenesis.