Background
Normal breast myoepithelial cells have been shown to exhibit tumour-suppressor activity mediated, in part, by downregulation of MMP expression [1]. DCIS myoepithelial cells have an altered phenotype as demonstrated by a different gene expression profile [2]. We have identified upregulation of α(v)β6 integrin on myoepithelial cells in a subset of DCIS; however, the role of α(v)β6 in this context is not clear. α(v)β6 is not expressed by normal epithelial cells, but is expressed in some cancers where it promotes tumour cell invasion and enhances MMP expression.