MGMT and central nervous system cancer: We characterized the MGMT promoter methylation status of four in vitro glioma models using methylation-specific PCR as either MGMT promoter-methylated (GBM1, JHH520) or -unmethylated (GBM10, SF188) supported by relatively low (GBM1, JHH520) or high (GBM10, SF188) IC50 values of TMZ (Table 1).