CD8A and neoplasm: Interestingly, cytotoxic CD8+ T cells in metastatic lymph nodes, but not in tumor infiltrating lymphocytes, are associated with favorable outcome in patients with OSCC [6], implicating that CD8+ T cells could mediate systemic protective immune response despite of the immunoselection or immunosuppression occurred locally in OSCC microenvironment [7]–[8].