CTLA4, PDCD1 and IDO1 differential expression does not exhibit significant prognostic impact in GBM patients. TCGA GBM-cohort (n = 540, A–C) and REMBRANDT GBM-cohort (n = 178, D–F) stratified (median) into “high-expression” (red; TCGA, n = 271; REMBRANDT, n = 89) or “low-expression” (black; TCGA, n = 269; REMBRANDT, n = 89) and represented as Kaplan–Meier plots (log-rank (Mantel-Cox) test; hazard ratios (HR)+95% confidence interval or CI).