SMN1 and ductal breast carcinoma in situ: The immunohistochemical detection of several biomarkers for myoepithelial cells, such as CD10/neprilysin/membrane metallo-endopeptidase [35], smooth muscle actin (SMA), calponin (CLP), and p63 [36], confirm the diagnosis of pure DCIS, while the gradual loss of these myoepithelial cell differentiation markers indicates a compromised myoepithelium, and suggests DCIS progression to invasive disease [34].