Similar to the observed induction of IL-33 in DSS-induced colitis, colon IL-33 and IL-33 receptor are upregulated in acute infectious colitis with Citrobacter rodentium. In this infectious model, IL-33 drives mucosal inflammation and impairs bacterial clearance through enhancing epithelial permeability and limiting the induction of Th17 cells35. Here, IL33 is linked to infectious colitis.