P2RX4 and neoplasm: The expression of P2X4R has been shown to be co-localised with the pro-inflammatory cytokine IL-1β in renal tubule epithelial cells [49,50], while a prolonged exposure to IL-1β induces necrosis in various cell types including tumour cells [50,51,52], although others have argued that IL-1β is more involved in inducing apoptotic cell death [53].