ITLN1 and colitis: This altered sensitivity to disease observed in TgVil1-Itln1 may be a consequence of mucus layer thinning, similar to the spontaneous colitis reported in Muc2−/− mice (Van der Sluis et al., 2006) and in gnotobiotic Il10−/− mice colonized with A. muciniphila (Seregin et al., 2017).