Using the “Population Comparison” tool from the Immunological Genome (ImmGen) Project, we next analyzed which genes are upregulated in these two cell subsets compared to late effector CD8+ T cells (T.CD8+EFF, OT-I; monitored at days 5, 6, and 8 post-infection with LIS and VSV; see methods). This evidence concerns the gene CD8A and infection.