IL4 and cerebellar ataxia: B6Nlrp1b(129S1);IL4−/− mice showed no alteration in the ERP or resistance to B. anthracis compared to B6Nlrp1b(129S1) animals, indicating this cytokine cannot, on its own, account for differences in hypothermia, ataxia, or resistance to B. anthracis between B6Nlrp1b(129S1) and B6.CAST.11M animals.