Previously, we have shown in patients transplanted with a 10/10-MUD with a HLA-DPB1 mismatch that HLA-DPB1 mismatches that resulted in a positive PIRCHE score had a higher risk for acute GVHD than those HLA-DPB1 mismatches with a PIRCHE score of zero (8). This evidence concerns the gene HLA-DPB1 and acute graft versus host disease.