Indeed, the only prognostic factors available for gliomas (including age, performance status, extent of primary resection and biomolecular markers: IDH status, 1p/19q co-deletion and the methylation of O6-methylguanine-DNA methyltransferase promoter metilation status) are obtained by the surgical sampling of primary glioma, and, since their stability over time is unclear, they are not capable of guiding therapeutic management during the course of the disease. Here, MGMT is linked to central nervous system cancer.