(a) type 1 DM (T1DM) that develops due to autoimmune destruction of pancreatic β-cells leading to total insulin deficiency; (b) type 2 DM (T2DM) that develops due to reduced or inadequate insulin secretion by β-cells mainly accompanied with insulin resistance; (c) monogenic DM including neonatal and maturity-onset in adolescents; (d) diabetes due to other causes including cystic fibrosis and pancreatitis, and/or drug/chemical-induced; and (e) gestational diabetes that develops during pregnancy and is usually diagnosed in the second or third trimester. The gene discussed is INS; the disease is diabetes mellitus.