Acute myeloid leukaemia (AML) with t(8; 21)(q22; q22) and AML with inv(16)(p13.1q22)/t(16; 16)(p13.1; q22) are together referred to as core binding factor (CBF) AML1–4, which constitutes approximately 5–8% of all de novo AML cases5–7. This evidence concerns the gene CEBPZ and acute myeloid leukemia.