Interestingly, starting IL-33 applications by day 6 after CR infection - when Th17 differentiation is already initiated - did not alter the disease progression, and no differences in the colonic IL-17A expression nor in Th17 cell numbers were observed (Supplementary Fig. 2a–e), suggesting a negative contribution of IL-33 at the early phase of CR infection. The gene discussed is IL17A; the disease is infection.