NUPR1 and glioblastoma: The goal of the study was to elucidate the clinical potential role of promoter methylation patterns of the MGMT, NUPR1, NDRG2, and GLI1 genes as epigenetic molecular indicator markers for GBM via, first, detecting and comparing the promoter methylation status of the four genes in GBM and NND samples using a quantitative PCR-based method.