PD-L1 is expressed by professional antigen presenters such as macrophages and dendritic cells, but also lymphocytes, and more rarely, tumor cells in TNBC; it remains unclear which PD-L1-expressing cell populations, and their spatial microenvironment, contribute to the clinical or therapeutic benefit seen in PD-L1 positive TNBC. This evidence concerns the gene CD274 and neoplasm.