HSCT: hematopoietic stem-cell transplantation; allo-SCT: allogeneic stem cell transplant; GvHD: graft-versus-host disease; GVL: graft-versus-leukemia; allo-HSCT: allogeneic hematopoietic stem cell transplantation; IFN-γ: interferon-gamma; AML: acute myeloid leukemia; SCT: stem cell transplant; BO: bronchiolitis obliterans; cGvHD: chronic graft-versus-host disease; SNP: single nucleotide polymorphism; BMT: blood or marrow transplant; AL: acute leukemia; aGvHD: acute graft-versus-host disease. This evidence concerns the gene IFNG and chronic graft versus host disease.