Increasing the NLI/ETO2 ratio in K562 cells induces γ-globin transcription. (A) The ratio of abundance of NLI/ETO2 at locations across the locus is plotted using the values obtained by ChIP assays shown in Figure 4. (B) The expression of γ-globin was monitored by quantitative RT-PCR after manipulating the NLI/ETO2 ratio in K562 cells. Cells were collected 48 hours after transfection with a control RNAi vector or with an ETO2 RNAi vector alone or together with an NLI-expressing vector (+, 2 μg; ++, 4 μg). Results were normalized to GAPDH and error bars indicate SD. *P < .05; **P < .001. The expression of BGL3 (C) and ϵ-globin (D) were monitored by quantitative RT-PCR after manipulating the NLI/ETO2 ratio in K562 cells exactly as described for panel B. (E) Western blot analysis was performed using Abs to ETO2 and NLI to confirm ETO2 knockdown and NLI overexpression. Actin served as the loading control.