CD8A and viral infectious disease: This apparent discrepancy is likely explained by the timing of the responses – early inhibition of the viral infection is detrimental, attenuating the ensuing antitumor response, whereas later clearance of infection by recruited CD8 + T cells does not negatively impact tumor clearance as by this time the virus has done its job – the antitumor response has been initiated, lymphocytes have been activated, and cellular recruitment is underway.