PROM1 and malignant colon neoplasm: Although both CD133− and CD133+ subpopulations of HCT-116 cells, a human colon cancer cell line, have been found to induce tumor growth in mouse models [22], the CD133− subpopulation of one human metastatic colon cancer cell line, LoVo, was found more resistant to 5-fluorouracil treatment than the CD133+ subpopulation [20].