IL1B and colitis: Administration of either exogenous IL-1β or IL-18 at a dose of 0.1 μg/kg, which did not affect the severity of colitis in WT mice, immediately after and 24 h after rectal administration of OXA prevented progression of colitis in NLRP3−/− mice as assessed by the histological score on day 1 of colitis induction (Fig. 6R,S).