Overall and event-free survival of NCI high-risk, Ph-negative, B-ALL patients by fusion and IKZF1 status. (A-B) The 5-year OS and EFS for patients with Fusion⁺ patients were 68% (95% confidence interval [CI], 39% to 85%) and 48% (95% CI, 22% to 70%), respectively, in comparison with 88% (95% CI, 79% to 93%) and 78% (95% CI, 67% to 85%) for fusion-negative patients. (C-D) The 5-year OS and EFS for patients with IKZF1 deletion were 66% (95% CI, 45% to 81%) and 45% (95% CI, 25% to 62%), respectively, in comparison with 90% (95% CI, 79% to 95%) and 81% (95% CI, 69% to 89%) for patients without IKZF1 deletion. (E-F) The 5-year OS and EFS were 62% (95% CI, 28% to 84%) and 44% (95% CI, 15% to 70%), respectively, for patients with both fusion-positivity and IKZF1 deletion in comparison with 91% (95% CI, 79% to 96%) (P = .005) and 83% (95% CI, 71% to 90%) (P = .006) for those with neither. Del, deletion.