In contrast to their well-established role in assisting CD8+ T cell activation (10), the direct function of CD4+ T cells as effector cells in antitumor immunity is less studied (11), although several reports have shown that a subpopulation of CD4+ T cells exhibits cytotoxicity against tumor cells with high levels of MHC-II (12–16). The gene discussed is CD8A; the disease is neoplasm.