CD274 and breast cancer: The lack of concordance of these markers, especially PD-L1 in the tumor and stroma compartments (Supplementary Fig. 5) could be explained by the expression of PD-L1 in macrophages and morphologically fibroblast-like cells in addition to TILs in breast cancer stroma, as previously described.37 Future studies focused on phenotype of these cells would provide further evidence.