EGFR and glioblastoma: Epidermal growth factor receptor (EGFR) is a 170-kDa transmembrane glycoprotein with an intracellular tyrosine kinase domain that is significantly overexpressed on the surface of cancer cells such as glioblastomas and breast, colon, bladder, ovarian, prostate, renal, gastric, and lung carcinomas, and has been utilized as an important target in actively targetable cancer therapy [27].