While impaired β cell function and insulin resistance are both important in the pathogenesis of T2D, the relative contribution of these two factors in the etiology of diabetes varies in different populations.52,53 In a comparison of insulin sensitivity and β cell function in four different ethnic groups, Asian Americans were more insulin resistant than other ethnic groups, despite less obesity.54 As highlighted earlier, increased visceral adiposity in Asians may be one important factor. The gene discussed is INS; the disease is obesity due to melanocortin 4 receptor deficiency.