The purinergic receptor P2X7 (P2x7r), an ATP-gated ion channel protein, and its main ligand, extracellular ATP, have recently been found to play an important role in promoting CD11b+ CD206+ P2x7r+ macrophage-mediated myocardial fibrosis during mouse chronic cardiac transplantation rejection [17] (Fig. 2C). Here, P2RX7 is linked to Myocardial fibrosis.