Assay differences, expression of PD-L1 by both tumor cells and infiltrating immune cells, geographic variability of PD-L1 expression within the tumor microenvironment, cellular localization of PD-L1 (membranous versus cytoplasmic), and the dynamic nature of the immune response lend further complexity to the development of immunologic biomarkers that reliably predict response to immunotherapy. Here, CD274 is linked to neoplasm.