MGMT and central nervous system cancer: Methylation of the O-6-methylguanine-DNA methyltransferase (MGMT) promoter, the promoter for TERT (which encodes telomerase), isocitrate dehydrogenase 1 (IDH1), and codeletion of chromosome arms 1p and 19q (1p/19q codeletion) are important markers for the molecular classification of gliomas [13, 14].