We tested genetic variants of genes involved in T2D (CCND2, CDKN1B, CDKN2A, CDKN2B, CENPA, EML4, ID3, HNF1A, IGF1, IGF2, IGF1R, INSR, IRS1, IRS2, TCF7L2) in 12 pmCRC patients with T2D and 10 pmCRC patients without diabetes (both had cancer as exclusive comorbidity) to address their involvement in CRC progression (see Materials and methods for patient selection). This evidence concerns the gene IRS1 and type 2 diabetes mellitus.