Elimination of tumor-forming capabilities of CD133+ cells in vivo in mouse brains by Lenti-BMI1-693. (A) Summary of tumor formation efficiency in tumor cells derived from the two pGBM mouse models. For CD133+ cells, each mouse was implanted with 1,500 cells; and for the CD133− cells, 100,000 cells/mouse. (B) Representative images of H&E-stained paraffin sections. Compared with huge intracerebral xenografts in IC-2305GBM cells transduced with non-target Lenti-shRNA, no tumor formation was observed in mice implanted with tumor CD133+ cells in which BMI1 gene expression was silenced by Lenti-BMI1-693.