TCF7L2 and type 2 diabetes mellitus: With the high-throughput genotyping technologies, genome-wide association studies (GWAS) not only confirmed the candidate genes such as PPARG[5], KCNJ11[6], TCF7L2[7] and WFS1[8], but also identified more than 70 novel loci for T2D risk [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20].