Whereas adoptive transfer of immune T cells from infected wild-type (WT) mice to infected athymic nude mice, which lack T cells but have innate immune cells capable of producing IFN-γ, is able to prevent reactivation of cerebral T. gondii infection in the recipients, the transfer of WT immune T cells to infected IFN-γ-knockout mice fails to prevent the reactivation of the infection (Kang and Suzuki, 2001). The gene discussed is IFNG; the disease is infection.