Recent developments in research on diabetes mellitus embrace basic disciplines such as physiology, biochemistry, morphology and evolving sub-specialities. Fundamental studies on the heterogeneous diabetic syndrome are oriented towards regulatory principles of cell metabolism, genetic control mechanisms of insulin biosynthesis and secretion, as well as autoimmune events implicated in selective destruction of pancreatic ß-cell. In parallel, efforts are made for a better understanding of normal versus impaired biological actions, both of insulin and insulin-like growth factor I, and the translocation process of glucose transporters in insulin-responsive target cells.