TCF7L2 and type 2 diabetes mellitus: Here, we aimd to investigate rs7903146 (IVS3C/T) and rs290487 (IVS3C/T) polymorphisms in TCF7L2 in a case-control study of a large population of Han Chinese people to confirm the association of these 2 polymorphisms in TCF7L2 and T2DM in Han Chinese people.