Immunohistochemical analyses of normal breast tissue, and in situ and invasive breast carcinomas aiming to identify markers of tumor progression have identified several genes that are differentially expressed between normal and DCIS-associated myoepithelial cells including SMMHC, CK5/6, CD10, calponin, and integrin αvβ615–21. This evidence concerns the gene MME and ductal breast carcinoma in situ.