CD8A and infection: It is well established that, after primary infection, healthy HCMV carriers maintain extremely high frequencies of HCMV-specific CD8+ cytotoxic T lymphocytes (CTLs) in their peripheral blood which are often dominated by CTLs which recognize IE antigens; up to 10% of effector memory CD8+ CTLs can recognize IE72 in some donors (78, –, 80).