CD4~+T helper cells not only activate CD8~+T cells,but also play a pivotal role in the gener- ation and maintenance of memorial cytotoxic T lymphocytes(CTL).In addition, it is shown that CD4~+T cells have direct anti-tumor function.However,CD4~+ CD25~+ regulatory T cells(Tregs) negatively control immune re-sponse,and play an important role in immunosuppression and immune escape, it is considered as a key reason for ineffective immunotherapy.In recent years,there is great progress in cancer immunotherapy,and relevant cancer vaccines have attracted a wide spread attention.