P2x3r. The P2x3 Receptor is an ATP-gated cation channel that has been implicated in pulmonary fibrosis, rheumatoid arthritis, pain perception, and synaptic transmissions, among many other diseases . The limited success in drug development targeting these type of receptors may be due to the difficulties to compete with their ATP binding-sites . Additional allosteric sites may be possible alternative therapeutic targets (reference ligand AF-219). No P2x3r have been targeted by DW-BEL.