EGFR and glioblastoma: Genetic alterations are widespread in GBM, including commonly the loss of heterozygosity (LOH) at 10q, isocitrate dehydrogenase (IDH) mutations, O6-methyl guanine-DNA methyltransferase (MGMT) promoter methylation, epidermal growth factor receptor (EGFR) amplification, tumor protein 53 (TP53) mutations [40, 41].