(a) Strong expression of ER in a ductal-invasive breast carcinoma. (b) Strong expression of PgR in a moderately differentiated breast carcinoma. (c) Complete membranous expression of HER2 in a high-grade breast carcinoma (3+). (d) Silver-enhanced in situ hybridization (SISH): multiple Her2 gene copies (black dots) in tumor cell nuclei of a Her2-amplified breast carcinoma. (e) Nuclear expression of Ki67 in a poorly differentiated breast carcinoma. (f) Focal perimembranous expression of CK5/6 in a high grade tumor. (g) Moderate cytoplasmic expression of COX-2 in a ductal-invasive breast carcinoma. (h) Diffuse cytoplasmic expression of YB-1 in invasive breast cancer nests.