EGFR and glioblastoma: Work from the Cancer Genome Atlas (TCGA) and others has molecularly categorized GBM tumors into the proneural, classical, and mesenchymal subtypes—marked predominantly by mutations causing platelet-derived growth factor receptor alpha (PDGFRa) activation, epidermal growth factor receptor (EGFR) activation, and neurofibromin 1 (NF1) deletions, respectively [11].