Cumulative incidences of A. sinusoidal obstruction syndrome (SOS), B. acute graft versus host disease (aGvHD) 1-4, C. treatment related toxicity (TRT) including aGvHD 1-4 and D. TRT including aGvHD 2-4. Results plotted for diplotype group IV (IV+) versus groups I, II & III (IV-). E. Overall survival (OS) in relation to GSTA1 extreme diplotype status (group I vs. group IV), in patients who received busulfan-cyclophosphamide conditioning regimen. Total number of patients represented by each curve with number of patients with indicated toxicities in parenthesis, and p value are depicted on each plot; group IV associated hazard ratios are depicted below each plot. F. Association of TRT with diplotype group IV in a competing events risk analysis. IV+ and IV- indicates the presence of this GSTA1 diplotype group. Competing events for TRT incidence were: death and relapse. p values for the difference in cumulative incidence of TRT, death, and relapse, between haplotype groups (IV vs others) is 0.000003, 0.3 and 0.5, respectively.