FGF-18 is a heparin-binding growth factor that belongs to the FGF family. Proteins of this family play a central role during prenatal development, postnatal growth and regeneration of a variety of tissues, by promoting cellular proliferation and differentiation. FGF-18 is an essential regulator of long bone and calvarial development. FGF-18 signals through FGFR 1c, 2c, 3c, and 4. Recombinant Human FGF-18 derived from E.coli is a 20.1 kDa protein consisting of 173 amino acid residues, resulting from C-terminal truncation of the full length protein.