BMI1 and neoplasm: Interestingly, BMI1 is overexpressed in cultured neurospheres from childhood brain tumors.4BMI1 overexpression was also reported in 53% of pHGG in situ and BMI1 inactivation in pHGG neurospheres impaired tumor formation in mouse xenografts.64,65 These findings thus indicate possible additional application for BMI1 inhibitors.