The category labeled “mismatch involving HLA-x” represents patients mismatched at HLA-x plus at least 1 allele at another locus. “Mismatch not involving HLA-x” represents patients who are mismatched for at least 2 alleles but not involving HLA-x. There were very few patients who were mismatched for both alleles at HLA-x, and for such patients there may or may not be another mismatch outside HLA-x for this category. Each locus was evaluated in a separate model, each model represented by a row in the table, which adjusted for the total number of mismatches and other non-HLA variables. The base model included patient age at transplantation, year of transplantation, use of ganciclovir for control of cytomegalovirus infection, use of fluconazole for prevention of fungal infection, and pretransplantation disease severity. Inclusion of HLA-DPB1 match status (all but 74 pairs) into the models did not alter the qualitative associations. - indicates the reference group.