Another subset of gliomas, the PDGFR subclass account for 25-30% of GBM, and is characterized by dysregulation of PDGFR activity, which in some cases is due to amplification and rearrangements of the PDGFRα gene locus, and in others to overexpression of the PDGF ligands[12, 18, 19]. The gene discussed is PDGFRB; the disease is glioblastoma.