CD274 and neoplasm: Pathological interpretations applied to PD-L1 immunohistochemistry (IHC) as a response biomarker are becoming more complex, going beyond simple Tumor Proportion Score (TPS) and requiring more complex diagnostic algorithms which evaluate the role of PD-L1 expression in 1) The tumor cells; 2) Immune cells in the Tumor Microenvironment (TME); and 3) Tumor infiltrating lymphocytes (TILs); all whose spatial relationships are critical for understanding the immune contexture.