Cumulative incidence of grade 2 to 4 acute GVHD by common HLA haplotype in patients with HP-P1. The endpoint was the time to the diagnosis of grade 2 to 4 acute GVHD with censoring of date of death until 100 days after transplantation. P value was calculated with the log-rank test. A total of 331 patients with HP-P1 were analyzed for the effect of another HLA haplotype by HP-P1, HP-P2, HP-P3, and the other haplotypes, which were lumped together.