CD4 and neoplasm: The first efforts to active CD4+ TH1 anti-tumor immunity were actually implemented through the generation of peptide-based vaccines, whereby immunogenic class II peptide fragments from tumor associated antigens such as MUC1 (209), NY-ESO1 (210), MAGE-A3 (211), and HER2 (212) have been injected to induce antigen-specific CD4+ TH1 response (1).