EGFR and glioblastoma: The phosphatidylinositide 3-kinase (PI3K) pathway is frequently overactivated in glioblastoma due to PIK3CA mutations, loss of phosphotase and tensin homolog (PTEN) gene function, and amplification of epidermal growth factor receptor (EGFR) gene expression (Sami and Karsy, 2013; Langhans et al., 2017; Colardo et al., 2021).