Inhibition of apoptosis in cells transduced with the Hemgn or the HOXB4 vector. (A) A representative experiment in which primary murine bone marrow cells were transduced with the indicated vectors, grown for 6 days in complete medium, washed, and then cultured for 16 hours in serum-deprived medium without cytokines to induce apoptosis. (Left panel) Gating for transduced cells (GFP/YFP⁺). The gated nontransduced cells serve as internal negative controls for transduction. Staining within each population for annexin V and PI is shown in middle and right column. (Middle column) Results for the nontransduced cells. (Right column) Gated, transduced cells. The percentage of apoptotic cells is indicated in the lower right quadrant for each sample. (B) Quantification and statistics of 3 biologically independent experiments showing the proportion of apoptotic cells for the 3 vectors and for the control, nontransduced cells in each sample.