One of the main risk variants associated with T2DM, TCF7L2, was also associated with colorectal cancer.37,38 Additionally, two genetic determinants of T2DM, HNF1B and JAZF1, were found to be associated with lower risk of prostate cancer.39 In contrast to T2DM, very few studies have reported the genetic correlation between T1DM and cancer. The gene discussed is TCF7L2; the disease is type 1 diabetes mellitus.