CD4 and neoplasm: TDEVs can decrease the antigen‐presenting ability of M2‐like TAMs and raise the generation of cytokines such as TGF‐β, IL‐10, and PGE2.[34, 51, 54] TGF‐β mediated by TAMs can not only prevent NK (natural killer) cells from killing tumor cells, promote dendritic cell (DC) apoptosis and reduce its migration rate, but also promote the differentiation of CD4+ T cells into the Th2 phenotype, and then inhibit the anti‐tumor activity of CD8+ T cells.