After infection with human immunodeficiency virus (HIV) or, in nonhuman primates, simian immunodeficiency virus (SIV), CD8+ T cells are stimulated from the naïve pool and subsequently develop effector functions that contribute to the antiviral response [1–3] including cytotoxic functions [4] and release of cytokines and chemokines [4–7]. Here, CD8A is linked to infection.