The objective of this study is to investigate the predictive role of O6-methylguanine-DNA methyltransferase (MGMT) and isocitrate dehydrogenase (IDH) status on the efficacy of bevacizumab (BEV) in high-grade glioma (HGG), while excluding the interference of chemotherapy agents. This evidence concerns the gene MGMT and malignant glioma.