LEF1‐AS1 and LEF1 expressions in myeloid malignancy were quantitatively evaluated by quantitative real‐time polymerase chain reaction (qRT‐PCR) using mononuclear cells isolated by Ficoll‐Hypaque separation from bone marrow samples of 15 controls, 12 MDS patients and 28 AML patients. The gene discussed is LEF1; the disease is myelodysplastic syndrome.