EGFR and glioblastoma: It has been reported that EGFRvIII is not expressed in normal brain tissue [19], while about 50% of patients with GBM expressing EGFR have EGFRvIII (+) [6], and EGFRvIII (+) is closely related to the poor prognosis of GBM patients and chemoradiotherapy resistance [20,21,22].