Because an increasedproportion of CD8+ T cells producing TNF-α was alsodetected in the spleen of N. caninum infected mice (Fig.5a), we tested the possible contribution of TNF-α toprotection using TNF-α-deficient(Tnf−/−) mice.Infected Tnf−/− mice and WTcontrols presented similar parasitic burdens in the brain(4.39 ± 0.51 vs4.84 ± 0.61 log10 parasites/mgDNA, respectively; P = 0.3027,n = 4) and lungs(3.33 ± 0.88 vs3.23 ± 2.18 log10 parasites/mgDNA; P = 0.9348, n = 4),7 days upon i.p. infection. The gene discussed is CD8A; the disease is infection.