Reciprocally, anti-tumor immune cell-derived EVs, such as those from CD8 + T cells or M1 macrophages, exert anti-tumor effects by enhancing cytotoxic activity or inhibiting tumor stromal cell formation, while pro-tumor immune cell-derived EVs, such as those from MDSCs and M2 macrophages, promote tumor progression by dampening anti-tumor immunity. This evidence concerns the gene CD8A and neoplasm.