BMI1 and cancer: In addition, BMI1 (polycomb protein family member) involved in stem cell self-renewal and cancer stem cell maintenance [10] is also significantly downregulated (Figure 3(a)), which seems to reflect in tumorigenic potential of U87 cells in the presence of AR-A 014418 (GSK3beta inhibitor) but not with Akt inhibitor studied using protocol of soft agar assay (Figure 3(b)), suggesting that the tyrosine phosphorylation of GSK3beta kinase is critical in regulating the colony formation (Figure 5(c)).