CD4 and cancer: It has been found that cancer cells, but also myeloid-derived cells, tumor stroma cells, and CD4+ regulatory T lymphocytes, may lead to immune cell inactivation by promoting excretion of suppressive cytokines such as IL-10 (interleukin-10) and other chemical mediators such as TGF-beta (tumor growth factor-beta), which inhibit immune cell infiltration and amplification, and production of inflammatory cytokines [28,29,30].