INS, IAPP, GCK and KCNJ11 methylation differed significantly between T2DM patients and healthy individuals (p = 0.001, p < 0.001, p < 0.001 and p < 0.001, respectively), while ABCC8 methylation did not differ between groups (p = 0.534) (Figure 2). Here, GCK is linked to type 2 diabetes mellitus.