In order to improve our knowledge of the intrinsic radiosensitivity of CSCs generated during EMT in breast tumors, we chose to work with purified CD24+/CD44low and CD24−/low/CD44+ cells obtained after induction of EMT by transforming growth factor β (TGFβ) in immortalized human mammary epithelial cells (HMLE). Here, CD24 is linked to breast neoplasm.