TCF7L2 and type 2 diabetes mellitus: In the analysis of TCF7L2 rs290481 T>C SNP, differences in the distribution of the rs290481 TC genotype compared with the rs290481 TT genotype and rs290481 TC/CC genotype compared with the rs290481 TT genotype between 502 T2DM cases and 782 controls were found [TC vs. TT: crude odds ratio (OR) = 1.29, 95% confidence interval (CI) = 1.01–1.65, P = 0.042 and TC/CC vs. TT: crude OR = 1.27, 95% CI = 1.01–1.61, P = 0.044 (Table 3)].