Fourth, we examined cytokine levels in the mouse serum and found that the levels of proinflammatory cytokines, IL-1β, IL-6, TNF-α, IL-12, IFN-γ, and IL-17, which have been previously described to control TB (29), were significantly increased in the serum of CSE−/− mice after 2 or 3 wk of infection (Fig. 3R). This evidence concerns the gene IL6 and tuberculosis.