To identify the cytokines produced by effector and memory T cells surviving into the phase of premunition and their dependence on persistent parasitemia, we measured IFN-γ, TNF, and IL-2 production by BrdU+ T cells in the spleen using intracellular cytokine staining after BrdU labeling from day 20 to day 30 (Fig. 5C and E). This evidence concerns the gene IFNG and parasitic infectious disease.