In the DSS-induced colitis model, IL-33 administration was found to exacerbate intestinal inflammation, while IL-33KO mice were protected against colitis.181–183 Hence, while this cytokine could be a therapeutic tool to prevent microbiota encroachment, its exact role in modulating the host/microbiota relationship remains to be fully elucidated. The gene discussed is IL33; the disease is colitis.