CD4 and neoplasm: One is antitumor cells mainly composed of CD4+ Th1 cells, CD8+ cytotoxic T lymphocytes (CTLs), NK cells, M1 macrophages, and dendritic cells, while the other is capable of promoting tumor growth and includes CD4+ FOXP3+ T cells (Tregs), CD4+ Th2 cells, and M2 macrophages [47].