CD274 and neoplasm: Indeed, we (and others) showed that in various tumor cells, PD‐L1 was secreted in EVs (Figure 2D–F, Figure S2F, S2G, Supporting Information).[25] In addition, PD‐L1 in EVs has been reported to suppress the function of CD8 T cells, and hence facilitate tumor growth.[25, 26] We, thus, quantified the concentration of EVs in the culture medium of control or 6J1‐treated cells with a nanoparticle analyzer.