G protein-coupled receptor 54 is a Metastin Receptor. Metastin, also known as KiSS-1, is a metastasis suppressor gene. Mutations in GPR54 have been shown to cause autosomal recessive idiopathic hypogonadotropic hypogonadism in humans and mice, suggesting that GPR54 is a key regulator for the onset of puberty (Seminara et al. 2003).