A study done by Krause et al. on individuals with T2DM reported a reduction in the extent to which IRS2 is expressed in the liver of individuals with obesity and T2DM, and this downregulation of IRS2 correlated with DNA methylation of hepatic IRS2 at the CpG5 island present near the promoter region [62]. The gene discussed is IRS2; the disease is obesity due to melanocortin 4 receptor deficiency.