PDGFRB and glioblastoma: In addition to EGFR genetic alterations, amplification/mutation in platelet-derived growth factor receptor (PDGFR), c-Met, Tie, Axl, discoidin domain receptor 1 (DDR1), erythropoietin-producing human hepatocellular carcinoma (Eph) also play a role in GBM biology [20].