Acidic and basic fibroblast growth factors (FGFs) are members of a family of multifunctional polypeptide growth factors that stimulate proliferation of cells of mesenchymal, epithelial and neuroectodermal origin. Like other growth factors, FGFs act by binding and activating specific cell surface receptors.These include the Flg receptor or FGFR-1, the Bek receptor (or FGFR-2), FGFR-3, FGFR- 4, FGFR-5 and FGFR-6. These receptors usually contain an extracellular ligandbinding region containing three immunoglobulin-like domains, a transmembrane domain and a cytoplasmic tyrosine kinase domain.