As expected, Vβ4+ CD8 T cells were increased upon M1 expression in WT MHV68 infection (Supplementary Figure 2e), but were not induced upon vaccination with either RDV-50.stop∆M1-M4 that lacks M1 or RDV-50.stop that do not express M1 transcript [23]. The gene discussed is CD8A; the disease is infection.