CD8A and infection: Although cognate Ag was not needed for continued granzyme C expression, we next queried whether TCR engagement during secondary infection could upregulate granzyme C. As before, we transferred 1 x 104 naïve OT-I CD8+ T cells into Cd8a-/- mice and infected both ears with VACV-NP-S-eGFP (containing cognate Ag) to establish OT-I CD8+ TRM in both ears under the same conditions.