IKZF1 and acute lymphoblastic leukemia: While DFS improved following the inclusion of imatinib for patients with Ph+ ALL, those with co-existing IKZF1 deletion continued to have an inferior 4-year DFS of 56% versus 75% in those without an IKZF1 deletion, confirming the negative prognostic impact of IKAROS deletions in children with Ph+ ALL [61].