In both GBM and normal donor brain CD45-negative cell fractions, presumably comprised of tumor or normal brain cells, we saw low percentages of PDL1-positive cell staining from normal donors (mean 10.6%), with higher percentages of GBM (32%) staining PDL1 positive, though the GBM samples showed high variability, with between 5-70% (Figure 3C). This evidence concerns the gene CD274 and glioblastoma.