CD4 and cancer: CD8 T cells are key anti-tumor effector T cells, and CD4 T cells can be further differentiated to perform various functions (for instance, to differentiate into CD8 memory T cells to suppress tumor growth) (36, 39, 40); however the M2 macrophages can also suppress anti-tumor immune responses by secreting multiple mediators such as the inhibitory cytokines IL-10 or TGF-B, down-regulating antitumor immune response, promotion of angiogenesis, enhancement of cancer cell proliferation, invasion, intravascular penetration, and spread have been metastasized (41–44).