Studies have also linked the MaSC hierarchy with the profile of tumor initiating cells/BCSCs characterized by CD44+/CD24- and ALDH+, where, CD44+/CD24- correspond to the MaSC population (EpCAMlow/-/CD49fhigh/+) and ALDH+ correspond to the luminal progenitor (EpCAMhigh/+/CD49fhigh/+) cells (29). This evidence concerns the gene CD44 and neoplasm.