P2RY1 and neuroblastoma: ADP is a potent pro-aggregatory agent, which is released during TCIPA induced by fibrosarcoma, breast carcinoma and neuroblastoma cells (36,42,43), whereas the ADP scavenger apyrase (35,42), ADP receptor antagonist ticlopidine (36) and ADP receptor inhibitor 2-methylthio-AMP (43) inhibit TCIPA.