Unlocking the secrets of the pancreatic beta cell: man and mouse provide the key.

Failure of the pancreas to secrete sufficient insulin results in type 2 diabetes, but the pathogenesis of pancreatic beta cell dysfunction is still poorly understood. New insights into beta cell failure come from defining the genes involved in rare genetic subtypes of diabetes and creating appropriate animal models. A new mouse model of transient neonatal diabetes mellitus emphasizes that both the number of beta cells and their function are critical for insulin secretion and may be regulated by imprinted genes.