Elongator complex protein 3, also named KAT9, is a protein that in humans is encoded by the ELP3 gene.[5][6] ELP3 is the catalytic histone acetyltransferase subunit of the RNA polymerase II elongator complex, which is a component of the RNA polymerase II (Pol II) holoenzyme and is involved in transcriptional elongation. ELP3 supports the migration and branching of projection neurons through acetylation of alpha-tubulin in the developing cerebral cortex.[7] In mammals, ELP3 is important for paternal DNA demethylation after fertilization.[8] ELP3 is potentially involved in cellular redox homeostasis by mediating the acetylation of glucose-6-phosphate dehydrogenase.[9] Besides, ELP3 may play a role in chromatin remodeling and is involved in acetylation of histones H3 and probably H4.