LY6S and neoplasm: A subpopulation of tumour cells, identified by co-expression of epithelial cell adhesion molecule (EPCAM), the basal cell marker NGFR, and the bronchioalveolar stem cell (BASC) marker stem cell antigen-1 (SCA1, also known as LY6A), was found to have the ability to propagate the tumour upon implantation into immunocompromised mice73.