Effect of different treatments on apoptosis and survival of B-CLL cells in vitro. Response of B-CLL tumor cells to different treatments shown by annexin V assay at 0, 24, 48, and 72 hours. Cells received no treatment (♦ and bold solid line), 5 Gy gamma ionizing radiation (• and dotted line), 20 μM fludarabine (▴ and dashed line), or 5 μg/mL CYC202 (▪ and thin solid line). Percentage of apoptotic cells in (A) all samples (n = 26), (B) ATM/TP53 wild-type B-CLLs (n = 15), (C) ATM mutant B-CLLs (n = 7), and (D) TP53 mutant B-CLLs (n = 4). Graphs represent mean proportion of apoptotic cells at each time point, and error bars represent 95% confidence intervals.