Frequent copy number changes are also noted in gliomas, particularly those having higher grade malignancies. Gain of chromosome 7 is associated with epidermal growth factor receptor (EGFR) amplification in gliomas. EGFR amplification is reported in GBM at a frequency of 30-40% and is correlated with poor prognosis and increased progression to stage IV disease. Furthermore, EGFR mutations are also reported in gliomas and are associated with EGFR overexpression. EGFR overexpression is typically found without IDH1 mutation in high-grade gliomas. Despite EGFR overexpression in gliomas, treatment with EGFR inhibitors has not produced notable results (Oncotarget (2016) 7(22): 33440-33450).