MGMT and central nervous system cancer: This methylation damage to DNA can be remedied by a DNA repair enzyme, O6-methylguanine-DNA methyltransferase (MGMT), which can be epigenetically silenced according to its promoter methylation status, making the MGMT promoter methylation status a strong prognostic and predictive biomarker in glioma [3–5] that is routinely measured in the clinical evaluation of glioma patients.