TCF7L2 and type 2 diabetes mellitus: In addition, some other publications observed significant T2D risk associations in some exposure strata but not in the respective other, although no statistically significant interactions were reported.25, 52, 53, 59, 60, 64, 68, 75, 76 Potential G × D interaction for genetic variants in the TCF7L2 gene were most frequently investigated, while findings of other genetic variants were often limited to one publication only.