In addition, high CD44 and low CD24 (CD44+CD24−/low) [7], as well as elevated aldehyde dehydrogenase (ALDH) activity [8] and increased mammosphere-forming capacity [9], have been confirmed as methods that enrich for cells with characteristics of cancer stem cells (CSCs), as assayed by increased tumour initiation potential in transplantation studies. Here, CD44 is linked to neoplasm.