The first genes revealed were CAPN10 and TCF7L2, but other genes were considered candidates to play a significant role in the pathogenesis of T2DM, such as PPARG, IRS1, and IRS-2, KCNJ11, WFS1, HNF1A, HNF1B, and HNF4A [42]. This evidence concerns the gene HNF4A and type 2 diabetes mellitus.