Relaxin-3 (H3 relaxin, Insulin-like peptide-7, INSL7) is a secreted protein structurally related to insulin, which is expressed primarily in the brain and central nervous system. Relaxin-3 has been identified as the ligand for the GPCR135 receptor, previously known as ``somatostatin-like'' or ``angiotensin-like'' peptide receptor, and also binds specifically to the LGR7 receptor, previously identified as an ``orphan'' G protein coupled receptor. Signaling by Relaxin-3 through its target receptors is, most likely, part of a CNS processing system, activated in response to signaling by neuropeptides and other factors. Intra cerebroventricular injections of Relaxin-3 have been shown to cause a significant increase of food intake and body weight in Wi