Cytotoxic CD8+ T cells play key roles in tumor immune surveillance.2 They recognize antigens presented by major histocompatibility complex (MHC) class I and typically require activation by antigen presenting cells (APC).3 Efficient T cell priming requires antigen capture and processing, peptide loading onto MHC molecules and provision of co-stimulatory signals. This evidence concerns the gene CD8A and neoplasm.