Overexpression of PD-L1 is found acrossmany tumor types, including metastatic triple negative breast cancer(TNBC).26−28 Targeting immune checkpoints with monoclonal antibodieshas revolutionized the treatment of several difficult-to-treat cancers,28 whereas small molecule inhibitors of PD-L1 havealso shown promising pro-immune antitumor effects in preclinical models.29 Nonetheless, despite their success, immunotherapyis in most cases insufficient to eradicate metastatic tumors in patientswith advanced cancer, even in combination with chemotherapy. This evidence concerns the gene CD274 and cancer.