Influence of HLA-B ME and class I ME in the GVH direction on grade 3-4 aGVHD. HLA-B ME (A) and class I ME (B) in the GVH direction is associated with higher incidence of grade 3-4 aGVHD.SHRs represent the effect of HLA-B ME and class I ME in GVH direction on grade 3-4 aGVHD as a continuous variable, adjusted for sex, age, HCT-CI, DRI, transplant protocol, conditioning regimen intensity, donor relation, stem cell source, and ABO match.