CD8A and neoplasm: CD8+ T cells provide protective immunity against a wide range of infectious pathogens such as HIV, influenza virus and CMV and some tumours, in many animal species and humans, suggesting that induction of CD8+ T cells by immunization could provide prophylactic or even therapeutic efficacy against a wide range of pathogens, particularly those that survive inside cells2, 3, 4, 5, 6.