Both H-2b- and H-2d-restricted CD8 T cell epitopes from D2B6F1 mice exhibited a greater frequency of IFN-γ and IFN-γ/TNF co-producing CD8 T cells than BCF1 mice following either Arm or Cl-13 infection (Fig 4A and 4C; S4 Fig). This evidence concerns the gene CD8A and infection.