IRS2 and metabolic disease: Previously, a 3% increase in IRS2 DNA methylation within a CpG island of exon 1 (cg05514401) was identified in subcutaneous adipose tissue of 15 insulin-resistant obese women concomitant with decreased IRS2 gene expression, as compared with 14 non-obese normoglycaemic women [11], indicating that IRS2 expression may be epigenetically regulated in metabolic diseases.