Effects of KLF4 overexpression on primary T-ALL cells. Primary T-ALL patient BM samples (n = 3) were transduced with either KLF4-GFP (KLF4) or GFP (CTL) lentiviruses. 72 hours after transduction, GFP+ cells were subjected to apoptosis assays as measured by Annexin-V binding and 7-AAD staining. Top, representative of flow cytometry profiles of primary T-ALL cells in apoptosis assays. Bottom, summary of percentages of apoptotic cells (Annexin-V + 7-AAD+) from three independent apoptosis assays. Data are represented as the mean +/- SEM. *P ≤ 0.05 versus bar 1 (for bar 2).