In contrast, the rapid effector response of memory CD8+ T cells can be beneficial when briefly activated in infections such as Listeriamonocytogenes, influenza A virus, Yersinia pseudotuberculosis, murine γ-herpesvirus, and Staphylococcus aureus (4, 9, 10, 12, 13, 17–19). The gene discussed is CD8A; the disease is infection.