IL-1 family member IL-33 is constitutively expressed in epithelial cells at barrier sites where it functions as an endogenous danger signal or alarmin following tissue damage.34,35 Although high levels of IL-33 are found in inflamed intestinal segments, how IL-33 functions in colitis has remained a formidable challenge due to diverse conclusions from previous studies.19,20,30,36–38 Our data suggested that delayed resolution of inflammation in the KIT Wsh mice was accompanied with a failure to reduce IL-33. This evidence concerns the gene IL33 and colitis.