CD133+ and CD133− cells were isolated from a panel of hepatocarcinoma cell lines, including HepG2, PLC 8024 and Huh78 and analyzed for their stem cell properties: CD133+ cells were shown to possess a greater colony-forming capacity in vitro, higher proliferative activity, greater ability to form tumors in vivo both using a subcutaneous and orthoptic tumor model and displayed also the capacity to differentiate into non-hepatocyte-like, angio-myogenic-like lineages [123]. This evidence concerns the gene PROM1 and neoplasm.