The fact that the treatment of macrophages with IL-17A plus IFN-γ is more efficient to eliminate the parasite compared with single-cytokine stimulation, might explain the higher mortality ratio in IL23p19KO and IL-17AKO mice even though the Th1 immune response, measured by IFN-γ production and the iNOS expression, is not impaired during the infection in both KO mice (52). This evidence concerns the gene IFNG and infection.