Orphan receptor. May bind to a neuropeptide and may regulate nociceptor function and/or development, including the sensation or modulation of pain (By similarity). Gut, vas deferens, uterus and aorta; barely detectable in liver, kidney, lung, and salivary gland. In the brain, markedly abundant in the cerebellum. Belongs to the G-protein coupled receptor 1 family. Mas subfamily.