PDCD1 and infection: Genes characteristic of T cell exhaustion were upregulated in the chronic LCMV infection (e.g., Pdcd1, Tox, Lag3), whereas genes associated with memory formation and inflationary phenotypes were upregulated in the acute LCMV (e.g., Il7r) and latent MCMV (e.g., Klrg1) infections (Figure 2A, Supplementary Tables S1–S3).