TCF7L2 and type 2 diabetes mellitus: However, another large cohort study of 5,327 nondiabetic men found that 8 T2DM-related genes (MTNR1B, TCF7L2, KCNJ11, HHEX, SLC30A8, CDKN2B, CDKAL1, and IGF2BP2) were associated with impaired early-phase insulin release, individually or in combination [219].