A P2X4- or P2X6- mediated Ca2+ influx in response to extracellular Zn2+ and ATP has later been shown to restore Cl− secretion across cystic fibrosis airway epithelia, suggesting P2X4 and/or P2X6 receptors as a potential therapeutic targets for the treatment of cystic fibrosis [466, 467]. Here, P2RX4 is linked to cystic fibrosis.