MGMT and glioblastoma: Some molecular markers including MGMT (O6-methylguanine DNA methyltransferase), IDH (isocitrate dehydrogenase), EGFR (epidermal growth factor receptor), and PTEN (phosphatase and tensin homolog) have been routinely tested in GBM patients clinically (van den Bent et al., 2017; Binabaj et al., 2018).