PDGFR(B) (Platelet-derived growth factor receptor, beta polypeptide) is a 190 kD cell surface tyrosine kinase receptor for members of the platelet-derived growth factor family. This family e, Xenopus/Amphibian,ist as several disulphide-bonded, dimeric isoforms (PDGF AA,PorcineDGF ABovine,PorcineDGF BBovine,PorcineDGF CC and PDGF DD) that bind in a specific pattern to two closely related receptor tyrosine kinases,PorcineDGF receptor ? (PDGFR?) and PDGF receptor (B) (PDGFR(B)). These growth factors are mitogens for cells of mesenchymal origin. PDGFRB is flanked on chromosome 5 by the genes for granulocyte-macrophage colony-stimulating factor and macrophage-colony stimulating factor receptor; all three genes may be implicated in the 5-q syndrome. A translocation between chromosomes 5 and 12, that fuses this gene to that of the translocation, ETV6, leukemia gene, results in chronic myeloproliferative disorder with eosinophilia.