However, obesity is considered to be one of the main factors in the development of T2DM and it is thought that this may be due to an increase in endogenous glucose production caused by hepatic insulin resistance, resulting in β-cell impairment and/or decreased insulin secretion due to amyloid deposition in the pancreatic islets, and as a result of β-cell failure, hypoinsulinemia and increased EGP production by the liver (54, 55). The gene discussed is INS; the disease is obesity due to melanocortin 4 receptor deficiency.