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. The gene discussed is CEACAM5; the disease is breast cancer.