During the last decades, CD8+ cytotoxic T lymphocytes (CTL) have been implicated as main effector cells in anti-tumor and anti-pathogen responses, since they were able to recognize and attack tumor or pathogen-infected cells presenting intracellular Ags derived from different non-self proteins on their surface through the interaction of the T cell receptor (TCR) with MHC class I peptide complexes [53]. This evidence concerns the gene CD8A and neoplasm.