Our study exposed an overall powerful association between eNOS T786C and T2DM susceptibility (TC vs. TT: OR = 1.28, 95%CI = 1.06–1.55; TC + CC vs. TT: OR = 1.31, 95%CI = 1.06–1.60; C vs. T: OR = 1.25, 95%CI = 1.04–1.49, Table 8; Figure 4). Here, NOS3 is linked to type 2 diabetes mellitus.