These include the RUNX1-ETO fusion, which is the most common cytogenetic abnormality in acute myeloid leukemia (9), and the ETV6-RUNX1 fusion, which occurs in ∼25% of cases of childhood precursor B cell acute lymphoblastic leukemia (10, 11). The gene discussed is RUNX1; the disease is B-cell acute lymphoblastic leukemia.