BMI1 and neoplasm: In summary, we demonstrated that BMI1 is over-expressed in pediatric gliomas, particularly in high-grade malignant gliomas, in both CD133+ and CD133− cells; and silencing this gene with lentivirus-mediated shRNA led to elimination of the tumor-forming capacity, particularly of CD133+ tumor cells, in vivo in two independent and patient-specific PDOX mouse models, thereby supporting the development of new targeted therapies against BMI1 in pGBM.