<h4>Background</h4>Microtransplantation (MST) combines chemotherapy with infusion of HLA-mismatched granulocyte colony-stimulating factor-mobilized peripheral blood stem cells (G-PBSCs) without graft-versus-host disease (GVHD) prophylaxis, offering a potential therapeutic alternative for older acute myeloid leukemia (AML) patients.<h4>Methods</h4>In this single-center study, 29 patients aged ≥60 years with newly diagnosed non-acute promyelocytic leukemia (AML) received MST between April 2008 and June 2021. Here, CSF3 is linked to graft versus host disease.