TCF7L2 and type 2 diabetes mellitus: When assuming 3 models (dominance, recessivity, and codominance) to explain the association between the rs12255372 (G/T) polymorphism of the TCF7L2 gene and T2D, the codominant model best fitted the association with an OR of 4.45 (95% CI 1.64 – 12.83, p = 0.0014)/OR (adjusted for age) of 4.33 (95% CI: 1.57 – 11.92, p = 0.005), thus a 4-fold risk increase.