KRT5 and ductal breast carcinoma in situ: A novel p63/CK5/Her2/neu expressing subpopulation of cells that are ER−/PgR−/EGFR− were identified in the myoepithelial and luminal areas of clinical comedo-DCIS and tumors derived from unfractionated MCF10DCIS.com and MCF10DCIS.com-CK5high cells.