Genetic polymorphisms in genes associated with T2D, including CCND2, CDKN1B, CDKN2A, CDKN2B, EML4, HNF1A, ID3, IGF1, IGF1R, IGF2, INHBA, INSR, IRS1, IRS2, and TCF7L2, have been implicated in promoting a more aggressive neoplastic phenotype in diabetic colon cancer patients.29 Here, IRS1 is linked to type 2 diabetes mellitus.