CD274 and cancer: These oncomarkers are known to be involved in breast cancer proliferation with an aggressive phenotype (EGFR, Her2, MUC1,cMet, and cKit) [46–51], cancer metastasis and invasion (EpCAM, E-Cadherin, CD133, MUC1,cMet and cKit) [50, 52–55], stem cell properties (CD44, CD24, CD133) [54, 56] and immune response (PD-L1) [45], and also represent potential drug targets for breast cancer therapy (Her2, cMet, EGFR, MUC1, cKit, PD-L1).