When compared with type 4 in case-only analyses, higher smoking pack-years was associated only with higher risk of type 14 (Pdifference = 1.8 x 10-5) and type 1 CRC (MSI-H, CIMP+, BRAF-mut, and KRAS-wt; Pdifference = 2.5 x 10-4). The gene discussed is KRAS; the disease is colorectal carcinoma.