The ten–eleven translocation (TET) family proteins TET1, TET2 and TET3 constitute a novel family of dioxygenases, whose functions are to demethylate DNA sequence by converting 5-methylcytosine to 5-hydroxymethylcytosine.20 Pathologically, TET2 is frequently mutated in hematopoietic malignancies of the myeloid lineage, particularly in AML.21 Most recently, WT1 is found to physically interact with TET2 and recruit it to the target genes of WT1,22 suggesting that TET2 may be involved in the transcriptional activity of WT1 in AML. This evidence concerns the gene TET3 and acute myeloid leukemia.