High level of ADAR1 protein is a negative prognostic factor in patients with GBM. a H&E and immunohistochemical analysis on GBMs (n = 16), cerebral cortex and white matter tissues, showing synaptophysin (neuronal cell marker), GFAP (astrocyte cell marker), and ADAR1 proteins. One representative picture of both GBM and control tissues is shown (× 40 magnification), demonstrating that an upregulation of ADAR1 protein is observed in GBM tissues versus an unaltered ADAR1 mRNA level (Additional file 2, Fig. S1a). b Representative qRT-PCR (top panel) and western blotting (bottom panel) analysis of ADAR1 in different glioblastoma cell lines (U138MG, T98G, A172, U118MG, U87MG, LN18) compared to normal astrocytes (n = 3). Values are represented as means ± SD, ***p ≤ 0.001. c Kaplan-Meier survival plot of GBM patients (n = 16) stratified by low (black line) and high (red line) ADAR1 expression. Log-rank test, p = 0.0112; HR 3.088, 95% CI 1.050–9.082 (see also Additional file 2, Table 1).