Using flow cytometry, we found that the percentages and absolute numbers of IFN-γ (Figures 4A–C) and TNF-α (Figures 4D–F) producing CD4+ cells in spleens (Figures 4A–F) and liver (Figures S2A–F in Supplementary Material) of infected TSLPR−/− mice were significantly (p < 0.05–0.0001) higher than those of WT control mice, with the difference being more pronounced toward the advanced stage of the infection when TSLPR−/− mice were unable to control parasitemia (see Figure 1B). This evidence concerns the gene CD4 and infection.