Tumor grading, age, isocitrate-dehydrogenase 1 (IDH1) and methylation status of the DNA repair gene O-6-methylguanin-DNA methyltransferase (MGMT) promotor, performance status and extent of resection are considered for predicting clinical outcome (Kita et al., 2009; Weller et al., 2017). This evidence concerns the gene MGMT and neoplasm.