TNF and neoplasm: HCC cell-secreted miR-146a-5p can be delivered by exosomes into macrophages, switch the cytokine profile, and attenuate antigen presentation of macrophages through inhibiting the expression of IFN-γ and TNF-α and upregulating the expression of inhibitory receptors such as programmed death ligand 1 (PD-1) and cytotoxic-T-lymphocyte-antigen-4 (CTLA-4), promoting the production of alternatively activated M2-polarized tumor-associated macrophages [87] (Figure 5).