WFS1 and type 2 diabetes mellitus: Except for the Li study [13] due to the lack of allelic frequencies, the data from other studies and the current study were included in this meta-analysis to improve the power in evaluating the collective evidence on the relationships of these nine genetic loci to T2D, especially HHEX, IGF2BP2, TCF2 FTO, and WFS1 genetic loci.