In a series of established breast cancercell lines (MDA-MB-231, TMD-436, Hs578T, SUM1315, HBL-100, and MDA-MB-468), theauthors observed a high percentage (>30%) of CD44+/CD24−/low cells which were highly efficient in initiating a tumor in experimentalsettings, and concluded that those cell lines were composed mainly of cancerstem cells. Here, CD44 is linked to neoplasm.