Quantitative RT-PCR analysis after knockdown of BMI1. HDLM-2 and KM-H2 cells were lentivirally transfected with RNAi construct directed against BMI1. RQ-PCR analysis indicated an about 2-fold reduction in BMI1 expression in comparison to GAPDH. Correspondingly, expression of both HOXB9 and HOXB13 increased about 9-fold and 3-fold in HDLM-2 and KM-H2, respectively. Experiments were performed twice with similar results; error bars indicate SD.