Moreover, recruitment of immunosuppressive cells such as regulatory CD4+ T cells (Tregs), CD4+ T helper 2 (Th2) and B cells, tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs) can inhibit antitumor T cell responses and promote tumor proliferation, metastasis, and angiogenesis (11). Here, CD4 is linked to neoplasm.