From an immunohistochemical point of view basal-like breast cancers typically express basal cytokeratins such as CK5/6, CK17 as well as cadherin, and epidermal growth factor receptor (EGFR); however, there are no phenotypically patterns which “per se” allow us to define basal-like breast carcinoma. This evidence concerns the gene KRT5 and breast carcinoma.