Fibroblast Growth Factor-4 (FGF-4) also known as K-FGF is a heparin-binding growth factor of the FGF family.It was identified by its oncogenic transforming activity. FGF-4 and FGF-3 are located closely on chromosome 11. FGF-4 and its receptors (FGF R1c, 2c, 3c and 4) play an important role in the regulation of embryonic development, cell proliferation, and cell differentiation. FGF-4 is required for normal limb and cardiac valve development during embryogenesis.Recombinant human Fibroblast Growth Factor-4 (rhFGF-4) produced in E.coli is a single non-glycosylated polypeptide chain containing 177 amino acids. A fully biologically active molecule obtained by proprietary chromatographic techniques at GenScript, rhFGF-4 has a molecular mass of 19.4kDa as analyzed by reducing SDS-PAGE.