EGFR and glioblastoma: A recent proteomic analysis confirmed protein- and phosphorylation-level signalling abnormalities in the EGFR, PDGFR, and NF1 pathways in classical, proneural, and mesenchymal subtypes of GBM, respectively, further suggesting that these GBM subtypes may be uniquely susceptible to targeted agents (Brennan et al, 2009).