CD8A and neoplasm: N2 TANs also engage with other immune cells such as CD8+ T cells,42,152–154 NK cells,155 and TAMs156 through various mechanisms and recruit regulatory T cells, thereby shielding tumor cells from CD8+ T cell- and NK cell-mediated cytotoxicity and promoting an immunosuppressive TME.156–158 PD-L1+ TANs can inhibit the proliferation and activation of CD8+ T cells in some tumors.42,152,153 A study demonstrated a correlation between NO release by TANs isolated from tumors in vivo and TNF-α paracrine signaling by T cells.