AHR and infection: The protective roles of AHR in epithelial barrier function have largely been demonstrated in the context of barrier perturbation by infection or following injury with DSS10,12,16,19,22, indicating that AHR may have a prominent role in the reacquisition of colonic epithelial homeostasis post-injury; a process whose dysregulation could render epithelial cells susceptible to malignant transformation2,3.