TCF7L2 and type 2 diabetes mellitus: For example, two genotypes linked with the susceptibility of Type 2 Diabetes Mellitus (T2DM); rs7903146 SNP in the TCF7L2 gene [OMIM: 125853], a heterozygous modifier affecting drug response, and the rs4402960 SNP in IGF2BP2 gene [OMIM: 125853] a heterozygous risk factor modifier.