BMI1 and neoplasm: Our results indicated that BMI1 overexpression increased cell growth (Fig. 2c, d), colony formation (Fig. 2e, f), cell migration (Fig. 2g, h) and cell invasion (Fig. 2i, j) as well as tumor sphere formation (Fig. 2k, l) in WBBMI1 and PLCBMI1 cells compared to control cells (i.e., empty vector transfected cells, WBCtrl/PLCCtrl cells).