Many studies, including one review (published in 2013) reported that these studies were only successful in reviewing two genes [calpain-10CAPN10 and transcription factor 7-like 2 (T-cell specific, HMG-box) (TCF7L2)] (10) associated with Type 2 diabetes although this differs from what was reported earlier where three more genes HNF4A, ENPP1, ADIPOQ were included (78). Here, TCF7L2 is linked to type 2 diabetes mellitus.