CD4 and neoplasm: Particular cell types of the innate and the adaptive immune system can function in a tumor-promoting or inhibitory way with neutrophils, M2-polarized tumor-associated macrophages (TAMs), TH2 CD4+ T cells and TRegs generally considered as pro-tumor cells, whereas, M1-macrophages/TAMs, TH1 CD4+ T cells and cytotoxic CD8+ T cells are associated with anti-tumor functions (13).