TCF7L2 and type 2 diabetes mellitus: Among the identified genetic variants, polymorphisms in APOE (apolipoprotein E) and TCF7L2 (transcription factor 7 like 2) genes have been strongly linked to insulin resistance, dyslipidemia and atherosclerosis in different populations, thereby increasing the risk of coronary artery disease and T2DM [36,37,38,39].