P2RX7 and neuroblastoma: In neuroblastoma cells, P2X7 activation promotes HIF-1α level and VEGF secretion by activating PI3K/AKT/GSK3β/MYCN and HIF-1α/VEGF3 signaling pathways, upregulates the expression of HIF-1α and VEGF, and increases intracellular glycogen reserve (54).