The present findings indicate that THAP10 acts as a tumour suppressor in t(8;21) AML, suggesting that AML1‐ETO promotes leukaemogenesis via epigenetic suppression of THAP10. Therefore, THAP10 expression may predict a favourable clinical outcome of patients with t(8;21) AML. The gene discussed is RUNX1; the disease is acute myeloid leukemia.