CD274 and neoplasm: PD-L1 expression can be assessed using different scoring systems: the Combined Positive Score (CPS), which accounts for PD-L1 staining on both tumor and immune cells (cut-offs usually ≥1, ≥5 or ≥10); the Tumor Proportion Score (TPS), which measures the percentage of PD-L1–positive tumor cells only; and the Tumor Area Positivity (TAP), reflecting the proportion of the tumor area occupied by PD-L1–positive cells, mainly used in Asian trials.