IDH2 and glioblastoma: GBM with wt IDH is characterized by tumor protein p53 (TP53) mutations, phosphatase tensin homolog (PTEN) mutations and/or complete loss of chromosome 10, homozygous deletion of cyclin-dependent kinase inhibitor 2A/2B (CDKN2A/CDKN2B), mutation or overexpression of epidermal growth factor receptor (EGFR), and/or gain of the 7p chromosome arm, platelet-derived growth factor receptor 1 (PDFGRA1) mutations, neurofibromin 1 (NF1) mutations, E3 ubiquitin-protein ligase (MDM2) amplification, and methylguanine-DNA methyltransferase (MGMT) promoter methylation [10].