PROM1 and neoplasm: When 10,000 cells were subcutaneously inoculated in nude mice the number of implants developing tumor was 1/8 for CD133−CXCR4−, 2/8 for CD133+CXCR4−, 6/8 and 8/8 in cells respectively CD133−CXCR4+ and CD133+CXCR4+.