Consequently, some genetic alterations with major prognostic significance - such as inv(16)(p13.1q22)/CBFB–MYH11, t(8;21)(q22;q22)/RUNX1–RUNX1T1, single NPM1 mutations and CEBPA double mutations (CEBPAdm) - have been implemented into the World Health Organization (WHO) classification of AML.2 The gene discussed is RUNX1; the disease is acute myeloid leukemia.