Efforts to cure diabetes are now focused on restoring a physiologically-regulated population of insulin-producing cells to the patient. A number of animal models of beta cell regeneration have been employed to study the mechanisms of the process. Islet neogenesis, the regeneration of pancreatic islets from pancreatic stem cells, is arguably the least fraught with barriers to widespread use as a therapy for diabetes. These animal models have led to the description of the reg family of proteins that appear to be related to islet regeneration. Islet neogenesis-associated protein (INGAP) is an initiator of islet neogenesis in animal models and a peptide sequence from INGAP carries the biological activity. INGAP peptide has been shown to stimulate an increase in beta cell mass in mice, rats, hamsters and dogs. INGAP is also found in the pancreas in human pathological states involving islet neogenesis. The peptide has been tested in human clinical trials, with success being reported. The evidence points to INGAP as a major factor in stimulating islet neogenesis, and, therefore, may play a significant therapeutic role in diabetes.