Background：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 which include the Flg receptor （FGFR-1） and the Bek receptor （FGFR-2）, as well as FGFR-3, FGFR-4, FGFR-5 and FGFR-6. FGFR1OP2 （FGFR1 oncogene partner 2）, also known as HSPC123, is a 253 amino acid cytoplasmic protein that is expressed in spleen, thymus and bone marrow and is involved in wound healing under normal cellular conditions. Additionally, FGFR1OP2 may also exist as an aberrant fusion protein with Flg and it is thought that the FGFR1OP2-Flg mutant may play a role in the pathogenesis of stem cell myeloproliferative disorder （MPD）. Multiple isoforms of FGFR1OP2 exist due to alternative splicing events.
