Another constraining factor to the potential antiangiogenic power of P2X7, that is shown here to be expressed in tumor vessels in vivo and functionally required for vascular stabilization in vitro, may be related to an peculiar biophysical feature of this ion channel: its sensitivity to extracellular acidosis, a condition occurring at hypoxic sites of inflammation and cancer50. Here, P2RX7 is linked to neoplasm.