PARP1 and glioblastoma: PARP-1 median gene expression (log2) was retrieved from two normal brain cohorts (n = 172 and n = 44) and three IDH-1 WT GBM cohorts (n = 20, n = 70 and n = 74) including two stratified by O6-methylguanine-DNA-methyltransferase (MGMT) promoter methylation status where available.