TET3, a member of the ten-eleven-translocation (TET) family of genes, is a methylcytosine dioxygenase that catalyzes the conversion of methylcytosine to 5-hydroxymethylcytosine and is most abundantly expressed in hematopoietic cells. Unlike the related TET2 protein, mutations in TET3 have not been observed in any myeloid malignancies. TET3 has been shown to be involved in the demethylation of zygotic DNA before the first mitosis and has been suggested to be involved in the epigenetic reprogramming of the zygotic paternal DNA following natural fertilization and may also contribute to somatic cell nuclear reprogramming during animal cloning.Synonyms: KIAA0401, TET3