Further, titering infected tissues of these mice showed no statistically significant differences in CNS or peripheral organ viral titer (S1G Fig). Since the cerebellum of Il1r1l–/–mice showed an increase in viral titer (S1D Fig), and to assess the effect of IL-33 on CNS viral restriction over time we intracranially infected Il33–/–and congenic controls with WNV-E218A, and collected CNS and peripheral tissues at early or late timepoints, corresponding to day 4 (Fig 1E) and 14 (Fig 1F) post-infection, respectively. This evidence concerns the gene IL33 and infection.