[
Genes Dev,
2003]
Obesity and the occurrence of diabetes are on the rise. Much of this is attributable to a more sedentary lifestyle and high caloric intake in industrialized countries and is a major cause of a variety of health problems. Obesity and diabetes are intimately linked to insulin, which increases glucose uptake in cells and serves as a primary regulator of blood glucose levels. Insulin has been an important target of investigation for decades, as indicated by its sequence determination by Sanger and colleagues in 1955, and is now the subject of renewed interest.