Minimal residual disease (MRD) after chemotherapy can predict the relapse of t(8;21) AML (3–6), and allogeneic hematopoietic stem cell transplantation (allo-HSCT) can further decrease relapse and improve survival in patients with persistent RUNX1-RUNX1T1 after chemotherapy (5, 7–9). The gene discussed is RUNX1T1; the disease is acute myeloid leukemia.