IRF1 and colitis: 4 Since both human CARINH and mouse Carinh loci are positioned close to the 3′ end of IRF1/Irf1 (spanning 5.6 kb in human and 7.1 kb in mouse) (Supplementary information, Fig. S1a), we proposed that Carinh regulates its neighboring gene Irf1 to exert a protective effect against colitis.