The first series of T2D GWAS conducted in 2007 in populations of European ancestry identified eight loci at or near TCF7L2, SLC30A8, HHEX, CDKAL1, CDKN2A/B, IGF2BP2, KCNJ11, and FTO [28–31]. Here, TCF7L2 is linked to type 2 diabetes mellitus.