IL1B and infection: Infection with VACV deletion mutants ΔA49, ΔB13, and ΔB15, which lack molecules that inhibit NF-ĸB, caspase-1, and IL-1, respectively, did to provoke DC migration (Supplemental Fig. 3), revealing, at least, that deletion of these specific molecules from VACV could not rescue the migration phenotype observed in our model.