CD44 and leukemia: For example, CD44+CD24−/low and ALDH+ CSCs were characterised in breast cancer [16,17], along with CD133+CD44+ in colon [18,19], brain [20], and lung [21] cancer; CD34+CD8− in leukaemia [22]; CD44+ in head and neck tumours [23]; CD90+ in liver cancer [24]; and CD44+/CD24+/ESA+ in pancreatic cancer [25].