These include type 1 diabetes (T1D), resulting from autoimmune β-cell destruction, usually leading to absolute insulin deficiency; type 2 diabetes (T2D), characterized by insulin resistance and a progressive decline in insulin secretion; and gestational diabetes mellitus (GDM), diagnosed in the second or third trimester of pregnancy in women without overt diabetes prior to gestation (2). The gene discussed is INS; the disease is type 2 diabetes mellitus.