EGFR and glioblastoma: Among the growth factor/receptor pathways that are thought to play a role, those involving the epidermal growth factor receptor (EGFR, also known as HER1) [5,6], the platelet-derived growth factor (PDGF) [6,7,8,9], and the vascular endothelial growth factor (VEGF) [10] are frequently activated in glioblastoma.