EGFR and glioblastoma: The four major genetic and epigenetic irregularities noted in GBM are derived from mutations in the metabolic enzyme isocitrate dehydrogenase 1 and 2 genes (IDH1/2), amplification in the epidermal growth factor receptor (EGFR), amplification of platelet derived growth factor alpha (PDGFRA), and the loss or mutation of neurofibromatosis type 1 gene (NF1) [1,3,4,5].