In mouse models of intestinal inflammation, AHR activation significantly improves, while its loss or the reduction of its endogenous ligand levels exacerbates dextran sulfate sodium (DSS)-induced colitis and bacterial-induced mucosal inflammation (Lamas et al., 2016; Li et al., 2011; Monteleone et al., 2011; Schiering et al., 2017). The gene discussed is AHR; the disease is colitis.