Especially, the MTNR1B rs10830963 presented a higher genetic effect size for GDM when compared to T2DM, and the odds ratios (ORs) of rs10830963 risk allele were generally ranged from 1.04 to 1.28 for T2DM, but from1.28 to1.84 for GDM [113,132,136,143,153,162,202–207] (Figure 7). This evidence concerns the gene MTNR1B and type 2 diabetes mellitus.