The CK5/CK14 monoclonal antibodies have been shown to be superior to CK5/6 and 34βE12. Cytokeratin 5/14 antibody may be used to identify basal cells in prostate and myoepithelium cells in breast cancer. Loss of epithelium staining along with p63 typically occurs in PIN (prostatic intraepithelial neoplasia) and prostate cancer. Additionally, CK5/CK14 + AMACR (P504S) may be added to the panel of antibodies used to assess neoplasia in prostate biopsies. Studies have shown that CK5/14 positive sporadic breast cancers arise from glandularly committed progenitor cells and represent about 9% of sporadic invasive ductal breast cancers and 78% of BRCA1-associated tumors.