CD8A and infection: The involvement of CD8+ T cells in viral control is evidenced by the concurrent emergence of virus-specific CD8+ T cells during peak viremia resolution in the acute phase of infection, the increase in viremia that follows experimental depletion of CD8+ T cells in SIV-infected rhesus macaques in both acute and chronic phases of infection, and the selection of viral CTL-escape mutations in response to the immunological pressure exerted by CD8+ T cells [1,2,3,4,5,6,7].