NFKB1 and colitis: Compared with REGγ−/−, colon epithelial cells from WT and REGγ/IκBɛ double-KO mice had dramatically higher expression of p-p65 (Fig. 6g), consistent with the p-p65 results observed in HCT116 shN, shR and dKD (REGγ and IκBɛ stable knockdown) cells (Supplementary Fig. 4B), supporting the contribution of NFκB activity to colitis.