Fibroblast growth factors (FGFs) are members of a large family of structurally related polypeptides that are potent physiological regulators of growth and differentiation for a wide variet of cells of mesodermal, ectodermal and endodermal origin. Four genes encoding for high affinity cell surface FGF receptors (FGFRs) have been identified: FGFR-1, FGFR-2, FGFR-3 and FGFR-4. FGFRs are emembers of the tyrosine kinase family of growth factor receptors. FGFR-1 is highly expressed in carcinoma tissue.