Regression tree analysis recursively identified 2 different Ang-2 cutoffs that predicted disease-free survival after HSCT for high-risk myeloid malignancy. The impact of the recursively identified (A) primary Ang-2 cutoff (< 4.18 vs > 4.18 ng/mL) and (B) a secondary cutoff (< 2.15 vs > 2.15 ng/mL) on disease-free survival were separately analyzed by log-rank test and displayed by Kaplan-Meier curves (P < .001 and P = .003, respectively).