KDR and glioblastoma: The in vitro studies presented herein also demonstrate the role of different members of the receptor tyrosine kinases (RTK) family, such as the vascular endothelial growth factor receptor (VEGFR); the insulin-like growth factor receptor-1 (IGFR-1); and the epidermal growth factor receptor (EGFR), in irradiation-induced GBM cell motility.