Previously it was shown that IRS2 expression is altered in obese individuals and in people suffering from non-alcoholic fatty liver disease (NAFLD) [5, 6]; however, it currently remains unclear as to whether IRS2 contributes to the pathogenesis of type 2 diabetes and fatty liver disease in humans, and the mechanisms responsible for IRS2 dysregulation are unknown. Here, IRS2 is linked to type 2 diabetes mellitus.