Recently, insulin treatment has become well defined as the default therapy in the following cases: (1) chronic treatment of type 1 diabetes mellitus, (2) events of acute dysregulated glycaemia (hyperosmolar hyperglycemia, diabetic ketoacidosis), (3) when fresh MI is the leading clinical determinant, in diabetes and nondiabetes cases, and (4) whenever insulin is a sole default agent since other antidiabetic medications are not feasible or rather contraindicated. The gene discussed is INS; the disease is type 1 diabetes mellitus.