An association between rs7903146 of the transcription factor 7-like 2 (TCF7L2) gene and the T2D risk was identified for the first time in a study of Icelandic, American and Danish subjects [4], and has since been consistently replicated in various European and non-European populations (including Indian and Japanese populations) [5-9]. The gene discussed is TCF7L2; the disease is type 2 diabetes mellitus.