These cytokine levels significantly dropped to lower than that of both the mutant-infected groups of mice on day 21 p.i. On the other hand, TNF-α was maintained at generally a similar level across all of the infected mice (with WT S. typhimurium or its ΔlppAB or ΔlppAB ΔmsbB mutants), but were elevated to much higher levels in both of the mutant-infected groups of animals at the later stages of infection (days 14 and 21, Figure 2F). The gene discussed is TNF; the disease is infection.