The beta cells of the pancreatic islets of Langerhans are the only cells in the body that produce and secrete insulin. This metabolic hormone plays a central role in the maintenance of glucose homeostasis, regulating glucose uptake in muscle and adipose tissue as well as carbohydrate, fat, and protein metabolism in these tissues and the liver. This book provides a comprehensive up-to-date review of the beta cell in health and disease. Chapters address the architecture and pathology of normal and diabetic pancreatic islets; regulation of beta-cell proliferation and death; the potential of stem cells and extra-pancreatic tissues as beta-cell replacement therapies; insulin biosynthesis; regulation of insulin secretion including metabolic control, ion channels, gap junctions, cyclic AMP, incretins, and exocytosis; development of novel imaging techniques; and genetic disorders of the beta cell. A primary aim of the book is to encourage students and young basic and clinical investigators to become actively involved in diabetes research and the search for new approaches to prevent and treat diabetes.