CD4 and neoplasm: On the other hand, high levels of cytokines and chemokines, including TGF-β, IL10 and CCL2 are secreted by PCa, which may contribute to the recruitment of various immunosuppressive cells (myeloid-derived suppressor cells and regulatory T cells) and tumor-promoting TAMs [54, 55], thereby promoting treatment tolerance and immune evasion by inhibiting CD4+ helper T (Th1) and CD8+ cytotoxic T cells [56].