Gonzalez-Sanchez et al. [11] found that the risk allele frequencies of rs7901695, rs7903146 and rs12255372 were significantly higher in T2DM patients compared with that in control subjects and suggested that genetic variant in the TCF7L2 gene were major genetic contribution of the risk of T2DM in Spain. This evidence concerns the gene TCF7L2 and type 2 diabetes mellitus.