PARP1 and glioblastoma: It has been documented that a pronounced enrichment of BMI1 after IR at the chromatin confers radioresistance in GBM through copurifying with NHEJ repair proteins, such as DNA-PK, poly [ADP-ribose] polymerase 1 (PARP-1), hnRNP U, and histone H1 in CD133+ GSCs [272].