RNASE4 and colitis: WT mice were cohoused with either age- and sex-matched Rnase4−/− mice (WT (co-Rnase4−/−)) or with WT littermates (WT (co-WT)) born from heterozygous Rnase4+/− parents for a period of 6 weeks prior to the induction of colitis (Fig. 4a).