They continuously patrol their periphery non-lymphoid niche and respond rapidly to local pathogen re-encounter by either direct lysis of infected cells or production of interferon-γ (IFN-γ) and inflammatory chemokines, which consequently result in the timely recruitment of circulating lymphocytes (e.g., memory CD8+ T cells, B cells, and innate leukocytes) to the site of infection to facilitate viral clearance (9–12). Here, CD8A is linked to infection.