A study on 72 thalassemia patients receiving unrelated HSCT confirmed that the risk of rejection was associated with the presence of non-permissive HLA-DPB1 mismatches in the host-versus-graft (HvG) direction, as predicted by the algorithm.21 TFS was reduced in patients with non-permissive HLA-DPB1 mismatches in HvG (59%) or GvHD (60%) direction, as compared to the matched or permissive group (78%). Here, HLA-DPB1 is linked to thalassemia.