The efficacy was attributed to vaccine-elicited CD8+ T cells that could retain their effector functions once infiltrated into the tumor [7], reduce myeloid-derived suppressor cells (MDSCs) and CD4+CD25+Foxp3+ regulatory T lymphocytes (Treg) cell populations [8, 9], and lead to the complete clearance of tumor cells [5, 7]. Here, CD4 is linked to neoplasm.