Given the co-expression of CD19 on both PTLD and AML cells, donor-derived CD19 CAR-T therapy was administered at a dose of 1×106 and 1.9×106 cells/kg after conditioning with fludarabine (30 mg/m2 per day) and cyclophosphamide (300 mg/m2 per day). The gene discussed is CD19; the disease is acute myeloid leukemia.