EGFR and glioblastoma: Phase II clinical trials with EGFR TKIs (ZD-1839, gefitinib; OSI-774, erlotinib) demonstrated some responses, but overall minimal improvement over historical controls in unselected patients.118,119 Because of the activation of mTOR due to the frequent loss of PTEN in GBM, mTOR inhibitors have also become exciting tools.