In addition, epithelial cells are positive for Mammaglobin A, GCDFP15, E-cadherin and strongly positive for HER-2, and supplemental information can reveal that the patient has been clinically confirmed with the occurrence of breast carcinoma metastasis at other sites (peritoneal, thoracic vertebrae, etc.), suggesting that the breast cancer is the source of the metastatic carcinoma. This evidence concerns the gene ERBB2 and breast cancer.