CD4 and neoplasm: The pro-tumor immune cells play an important role in blocking antitumor immune responses and shaping an immunosuppressive microenvironment and are represented mainly by the regulatory T cells (Tregs), myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAM), in particular M2-polarized macrophages, and group 2 innate lymphoid cells (ILC2s)., the majority of antitumor immune cells include effector T cells, such as cytotoxic CD8 + T cells and effector CD4 + T cells, natural killer cells (NK), dendritic cells (DC), and M1-polarized TAM (9).