EGFR and glioblastoma: Primary glioblastoma primarily occurs in older patients (mean age, 62–64 years) and typically shows epidermal growth factor receptor (EGFR) overexpression, PTEN mutations, cyclin-dependent kinase inhibitor (CDKN2A) (p16) deletion, and, sometimes, mouse double minute 2 homolog (MDM2) amplification [2].