Given these premises, we specifically wondered whether cytokines, which orchestrate many different aspects of the inflammatory process, could have a major role in MV release with respect to exATP. In order to clarify this point we used the human embryonic microglia cell line (CHME-5). Cell lines are unavoidable due to the fact that MVs are fragile structures scarcely produced by primary cell cultures; for any analyses, in contrast, huge amounts are necessary. In order to validate the model we checked the ability of CHME-5 cells to release MVs upon ATP treatment. The expression of the P2X7, the only receptor for extracellular purines so far related to membrane shedding (13), has been analyzed by flow-cytometry with respect to that of HEK-293T, a human cell line that does not express the receptor (14); Figure 2A shows that CHME-5 cells carry the P2X7 on their surface. Additionally, the expression of the receptor has been validated by RT-PCR and immunoblotting as well as by functional assays, i.e., ethidium uptake and calcium imaging (Figures S1A–D in Supplementary Material).