Specific relative cell viability (%) of B-ALL cells cultured alone with increasing concentrations of the GSI XII for 1 day. Percentage of live human B-ALL cells (annexin V⁻/7-AAD⁻; bottom left quadrant) was analyzed by using flow cytometric analysis. Percentage of specific apoptosis was calculated according to the following formula: (test [inhibitor-induced apoptosis] − control [spontaneous apoptosis]) × 100/(100 − control). Statistical analysis was carried out by using 1-way ANOVA, Holm-Sidak test. **P < .01. Data were represented as the mean ± SD of 10 independent experiments.