Plays an important role in the regulation of embryonic development, cell proliferation, cell differentiation and cell migration. Required for normal brain, eye, ear and limb development during embryogenesis. Required for normal development of the gonadotropin-releasing hormone (GnRH) neuronal system (PubMed:16384934, PubMed:16597617, PubMed:8663044). Plays a role in neurite outgrowth in hippocampal cells (PubMed:21576111). Monomer. Homodimer. Interacts with FGFR1, FGFR2, FGFR3 and FGFR4. Affinity between fibroblast growth factors (FGFs) and their receptors is increased by heparan sulfate glycosaminoglycans that function as coreceptors. Additional isoforms seem to exist. In adults expression is restricted to the gonads. The disease is caused by variants affecting distinct genetic loci, including the gene represented in this entry. The genetics of hypogonadotropic hypogonadism involves various modes of transmission. Oligogenic inheritance has been reported in some patients carrying mutations in FGF8 as well as in other HH-associated genes including FGFR1 (PubMed:23643382). The gene represented in this entry is involved in disease pathogenesis. Duplications encompassing the FGF8 locus have been found in unrelated families with isolated bilateral hypoplasia of the femoral and pelvic bone. The phenotype is most likely the result of position effects causing altered FGF8 expression rather than gene dosage. Belongs to the heparin-binding growth factors family.