FAS and neoplasm: When tumor cell EVs carry immune-modulatory proteins, these proteins may interact with specific receptors on immune cells to suppress immune cells.16,17 On the other hand, EVs secreted by immune cells were previously thought to exhibit anti-tumor properties.18,38 More recently, accumulating evidence suggest that immune cell-derived EVs may have pro-tumor effects.39,40 For instance, EVs-contained FasL derived from activated T cells was shown to promote melanoma evasion via the Fas/FasL pathway.39 However, the precise mechanisms remain elusive.