CD8A and neoplasm: Although the interaction between CD4‐positive T lymphocytes and CD8‐positive T lymphocytes in tumor immunity is only partially understood, it is possible that dendritic cells function as a platform that supports the interaction between CD4 and CD8 T lymphocytes, and that CD4‐positive T lymphocytes may have an important function in the expression of the anti‐tumor effects of CD8‐positive T lymphocytes [21].