CD4 and cancer: For example, CD8+ T cells, CD4+ Th1 cells, dendritic cells (DC), natural killer (NK) cells, and M1 macrophages mainly exhibited inhibitory effects on cancer progression, while regulatory T cells (Tregs), CD4+ Th2 cells, myeloid-derived suppressor cells (MDSCs) and M2 macrophages mainly show pro-tumor effects206.