Carcinoembryonic antigen (CEA)8,9, human epidermal growth factor receptor-2 (HER2)10,11, the oncogenic protein RS/DJ-112, tissue polypeptide antigen (TPA)13 tissue polypeptide specific antigen (TPS)14 and CA 15–315,16 have been recommended as biomarkers for metastatic BC, as they were deficient in early BC detection. This evidence concerns the gene ERBB2 and breast cancer.