As mentioned above, it is generally accepted that the most strongly associated locus with T2D is TCF7L2. The TCF7L2 gene encodes a high mobility group (HMG) box-containing transcription factor, which is the effector of the canonical Wnt signaling pathway that plays a key role in embryonic development [77, 78]. The gene discussed is TCF7L2; the disease is type 2 diabetes mellitus.