FGF-5 is a secreted heparin binding growth factor that belongs to the FGF family. Proteins of this family play a central role during prenatal development and postnatal growth and regeneration of a variety of tissues, by promoting cellular proliferation and differentiation. FGF-5 binds to FGFR 1c and 2c, and plays a regulatory role in the hair growth cycle. Recombinant human FGF-5 is a 27.6 kDa protein consisting of 252 amino acid residues.