The NPVF gene, and thus the propeptide, are expressed in neurons in the mediobasal hypothalamus.
[1] The propeptide is cleaved to form three other peptides, which are:[2][3] NPSF and NPVF, originally referred to as the RFamide-related peptides RFRP-1 and RFRP-3, respectively,[4] are the mammalian homologs of the avian neuropeptide gonadotropin-inhibitory hormone (GnIH).
[2] The mammalian NPVF and avian GnIH genes, along with their aforementioned peptide products, were discovered concurrently in 2000.
[1][2] Similarly to the avian GnIH neuropeptide, NPSF and NPVF have been found to potently inhibit gonadotropin secretion.
[5] Moreover, a potent and selective antagonist of the NPFF receptors, RF9, has been reported to possess "very strong" gonadotropin-releasing effects in vivo in male and female mice.