O'Brien and his team [4] identified CD133 positive cells shared the characteristics of human colon cancer-initiating cells, in which CD133 positive cells were able to initiate tumor growth in minor quantity of the cells Moreover, CSCs with CD133 positivity possessed strong carcinogenesis, cloning ability and proliferating capacity as demonstrated in many experiments [4-8,11,12,17], and were resistant to anti-cancer therapy [10,18]. Here, PROM1 is linked to cancer.