TCF7L2 and type 2 diabetes mellitus: Willmer et al. [8] also focused on differential methylation signatures in blood samples and reported TCF7L2, KCNQ1, ABCG1, TXNIP, PHOSPHO1, SREBF1, SLC30A8 and FTO genes to be reproducibly associated with T2DM across multiple population groups in the literature reviewed between January 2002 and July 2018.