Irf1−/− mice show active colitis in response to the irritant dextran sodium sulfate (DSS)16,17, and human IRF1 mRNA is increased in lamina propria mononuclear cells from CD patients18, thus suggesting that IRF1 may contribute to inflammation in IBD, and possibly to progression to CA-CRC. This evidence concerns the gene IRF1 and colorectal carcinoma.