IRS1 and type 2 diabetes mellitus: When the known T2D susceptibility genes represented on the array were specifically evaluated, we found that ADCY5, CAV1, CIDEC, CDKN2A, CDKN2B, DUSP9, HNF4A, IDE, IRS1, KCNQ1, MTNR1B, TSPAN8 and WFS1 had at least one CpG site differentially methylated between type 2 diabetic and non-diabetic twins in SAT.