TERT and glioma: Therefore, several important glioma biomarkers were included into the updated WHO classification system as potential therapeutic targets: MGMT (O6-methylguanine DNA methyltransferase) methylation, IDH1/2 (isocitrate dehydrogenase 1/2) mutations, EGFR (epidermal growth factor receptor) amplification, TERT (telomerase reverse transcriptase) promoter mutations, and PTEN (phosphatase and tensin homolog) deletions [2,9,10].