CASP1 and infection: Interestingly, these in vitro observations are not recapitulated in vivo, since total IL-1β levels in the lungs of Mtb-infected Asc and caspase-1/11 knock-out mice were not significantly different from wild-type mice and consistent with this result these mouse strains were less susceptible to Mtb-infection when compared to IL-1β- deficient mice [20], [23].