CD274 and breast cancer: In the clinic, the treatment strategy for HER2-enriched breast cancers is mainly by targeted therapy with trastuzumab in combination with chemotherapy, while basal-like/TNBC are treated with radiotherapy and chemotherapy until the recent development of olaparib for BRCA-mutated TNBC, and anti-PD-L1 immunotherapy in combination with chemotherapy for advanced disease [47, 48].