Thus, investigating two co-infection models which separated antigen-specific stimulation from the overall induced inflammatory milieu, we demonstrated that the dominant LCMV-induced inflammatory milieu determines the type I IFN dependence of the antigen-specific CD8 T cells, although LCMV was not involved in antigen-specific stimulation and the antigen-load and the quality of the antigen-presentation were not limited. The gene discussed is CD8A; the disease is coinfection.