During the acute infection, the reconstitution of cd8−/− mice with CD8+ T-cells from ifnγ−/−pfn+/+ donors (deficient in IFNγ but able to express Pfn) significantly favored the control of the parasite when compared with non-reconstituted mice, corroborating the reports that suggest the importance of Pfn in the protective immunity that controls T. cruzi during the acute phase of infection [7], [28]. This evidence concerns the gene CD8A and infection.