Engraphment, GVHD, disease progression/recurrence, and TRM observed in the study. Cumulative incidence of (A) donor cell engraftment, (B) acute GVHD, and (C) chronic GVHD after HLA-haploidentical HCT in patients who received a conditioning regimen containing reduced-dose busulfan, fludarabine, and ATG. Cumulative incidence of (D) progression/recurrence of acute leukemia/MDS and (E) TRM relative to disease status at HCT.