As reported before (Soboleski et al., 2011), CTL responses induced with S-FLU virus and recombinant adenovirus infection were comparable (in lungs and spleen); however, further investigation is needed to understand the differential cellular infiltration at tumour site following immunization with S-FLU or adenovirus and whether both viral infections induce a similar frequency and quality (polyfunctionality or tumour cell-killing effect) of tumour-infiltrating antigen-specific CD8+ T cells following infection. This evidence concerns the gene CD8A and viral infectious disease.