CD44 and urinary bladder cancer: One of the reasons for failure of traditional cancer therapies (such as surgery, chemotherapy or radiotherapy) is the existence of a small subpopulation in cancer, called as cancer stem (initiating) cell (CSC or CIC).9 Since the first application of CIC theory on leukemia in transplanted mice10, 11 and related experiment methods in breast cancer solid tumor about CD44+CD24- fractions,12 studies have sprung up in bladder cancer.13, 14, 15