CD4 and neoplasm: The precise mechanisms of eradication of tumor cells by the adoptive transfer of activated killer T cells and DCs are not clear, but it may be mediated mainly by the immune responses of cytotoxic killer T cells since an abrupt increase in IFN-gamma in ascites occurred after the treatment, cytotoxic activity of infiltrating T cells was detected against autologous tumor cells in ascites, and most of the cells recovered from the ascites after treatment were CD3-, CD4-, and CD8-positive T cells.