TRPV4, a member of the OSM9-like transient receptor potential channel (OTRPC) subfamily in the transient receptor potential (TRP) superfamily of ion channels.The encoded protein is a Ca²⁺-permeable, nonselective cation channel that is thought to be involved in the regulation of systemic osmotic pressure. Two transcript variants encoding different isoforms have been found for this gene.VROAC is a cation-selective channel that is gated by exposure to hypotonicity within the physiologic range. In situ hybridization showed that in the central nervous system, VROAC is expressed in neurons of the circumventricular organs, neurosensory cells responsive to systemic osmotic pressure. VROAC was also expressed in other neurosensory cells, including inner-ear hair cells, sensory neurons, and Merkel cells^.