{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Beta-type platelet-derived growth factor receptor (PDGFR-B) is a cell surface tyrosine kinase receptor involved in cell signaling, particularly in response to platelet-derived growth factor (PDGF), which is a mitogen for mesenchyme- and glia-derived cells. PDGF consists of two chains, A and B, which dimerize to form three functionally distinct isoforms, PGDF-AA, PDGF-AB and PDGF-BB. These three isoforms bind with different affinities to two receptor types, PDGFR-A and PDGFR-B. PDGFR-A can bind to both A and B subunits of PDGF, while PDGFR-B can only bind the B subunit. Ligand binding promotes either homo- or heterodimerization of the PDGFRs in a specific manner. PDGF-AA induces the dimerization of two A receptors, PDGF-AB induces dimerization of AA and AB receptors, and PDGF-BB induces the formation of three types of dimers, AA, AB and BB receptors. Translocation of the PDGFR-B gene with the Tel gene (also known as ETV6) is linked to chronic myelomonocytic leukemia (CMML), a myelodysplastic syndrome, and demonstrates the oncogenic potential of the PDGFRs."}]}]}