PROM1 and neoplasm: After 14-17 days, a tumor development led to death of 15 animals (including 8 in the CD133+ group and 7 in the CD133- group) after injection of 1 × 103 cells and 18 animals (including 10 in the CD133+ group and 8 in the CD133- group) after injection of 1 × 104 cells.