IL18 and infection: We also evaluated protein levels of IL-18, IL-1β, IL-1α, IL-6, and TNF-α in whole lung tissue from Mda5−/− and WT C57BL/6 mice 12 weeks after M. tuberculosis infection, and RNA levels of IFN-β, IL-1β, and IL-6 at 4 weeks after infection (Supplemental Figure 7, A–I), but did not find a statistically significant difference in the expression of these cytokines, except for IL-18, which was undetectable in 3 of 6 Mda5−/− mice compared with WT mice, and IL-1β, which was elevated in 3 of 6 Mda5−/− mice.