IKZF1 and acute lymphoblastic leukemia: In addition, Ribera reported that IKZF1 deletions conferred a higher relapse incidence (40% vs. 58%, P = 0.048) and worse 5-year overall survival (OS; 29% vs. 50%, P = 0.023) than IKZF1 undeleted in Ph− B-ALL (47).