CD274 and neoplasm: They found that although most tumors were positive for PD-L1 by testing with both techniques (61% with a minimum of 1% cells expressing PD-L1, 38% with a minimum of 5%), the amount of PD-L1-positive GBM cells in each tumor was relatively low and exceptionally heterogeneous among the different samples (median: 2.77%, range: 0–86%) [30].