Effects of different cell culture conditions on TonB cells with reduced target gene expression. Lentivirally transduced RFP⁺ TonB cells were stained for annexin V expression either in the presence of IL-3 (left) or in the presence of doxycycline to induce BCR-ABL and in the absence of IL-3 (right) after 6 days. Dot blots show RFP fluorescence on the y-axis and annexin V-FITC staining on the x-axis.