Urotensin II is a very powerful vasoconstrictive substance. The human Urotensin II receptor (UTIIR) was originally isolated as an orphan receptor (GPR14) in neural and sensory tissues. Urotensin II is expressed in various human tissues such as CNS, skeletal muscle, smooth muscle, pancreas, and heart. Recently, evidence has accumulated indicating that Urotensin II is also expressed in various kinds of tumor cells such as of adrenal tumors and neuroblastomas. In those cells Urotensin II was reported to stimulate cell growth.