The mammary myoepithelial cell - Cinderella or ugly sister?

The breast myoepithelial cell is the Cinderella of mammary biology. Althoug h its contribution to benign and some malignant pathologies is recognised, it has been largely neglected in molecular and biological studies. The reas on for this has been the perception that its role in normal physiology is c onfined to lactation and the belief that most breast cancers arise from lum inal epithelial cells. This review presents our perspective on its broader biological significance and its potential use as a model system for underst anding breast carcinogenesis.