In non-diabetic α-cells, glucagon secretion is regulated by several factors, notably by glucose, amino acids and free fatty acids;11,27,28 and the paracrine effectors insulin and somatostatin.9,29,30 Diabetes disrupts this fine regulation of glucagon secretion, resulting in glucagon hypersecretion and aggravation of hyperglycemia. The gene discussed is INS; the disease is diabetes mellitus.