Kaplan-Meier analysis of survival and rate of disease progression in patients in advanced phases following imatinib therapy according to deletion status. (A) Survival from initiation of imatinib was compared in 122 patients (15 with deletions and 107 patients without deletions). No survival differences were seen (P = .14). (B) Progression-free survival was compared in 121 patients (15 with deletions and 106 patients without deletions). Patients with deletions had a significantly shorter time to disease progression (P = .02).