CD274 and neoplasm: Interestingly, they also showed that diffuse PD-L1 expression was a risk factor for poor disease-free and disease-specific survival outcomes compared to marginal PD-L1 expression on the interface between tumor and stroma, raising awareness of the importance of tumor microenvironment and suggesting that PD-L1 heterogeneity in tissue may at least partly explain the different PD-L1 positivity results reported in the literature.