TCF7L2 and type 2 diabetes mellitus: The association of KCNQ1 rs2237892 was the strongest (P<8.5×10−18) while TCF7L2 rs7903146 showed the largest effect (OR [95% CI] = 2.09 [1.63–2.69]), albeit with rare allele frequency (0.034 in T2D patients; 0.019 in healthy controls).