Cytokeratin 7: a re‐evaluation of the ‘tried and true’ in triple‐negative breast cancers

Abstract

TNBCs are commonly negative for most immunomarkers indicative of breast origin, with the exception of CK7. As about one in five TNBCs showed only focal CK7 positivity, use of this marker must be interpreted with caution, especially in small samples, so that the possibility of a breast primary is not overlooked.