The following antibodies were used: rabbit anti-P2X7 (Alomone Labs), mouse anti-flotillin-1 (BD Bioscience), and rabbit anti-Ki67 (Novocastra). Phalloidin-488 was used to stain F-actin; the monoclonal antibody against desmoyokin-AHNAK (dA) was a gift of Prof. Jacopo Meldolesi (Università Vita-Salute San Raffaele, Milano, Italy). Rabbit anti-Alix (Millipore), goat anti-CD63 (Biorbyt), mouse anti-COX-IV (Cell Signaling Technology), rabbit anti-cleaved caspase-3 (Cell Signaling Technology), β-actin (Sigma). Oxidized ATP (oxATP), brilliant blue G (BBG), probenecid, imipramine, siramesine and actinomycin D (actD) and ethidium bromide were purchased from Sigma-Aldrich; ARL67156 and SR11302 were from Tocris. 10Panx was from Innovagen and 11R-VIVIT from Calbiochem. WP631 was a gift of Dr. Cinthia Farina (San Raffaele Scientific Institute, Milano, Italy).