Once the hematoxylin and eosin stained slides are examined, a decisioni can be made as follows: If the tumor was pure sarcomatoid, then it had to express at least 2 epithelial markers in the immunohistochemistry analysis (cytokeratin 5/6, high molecular weight cytokeratin, P63, pancytokeratin, CK7) for the diagnosis of MBC. Here, KRT7 is linked to neoplasm.