The BET, or bromodomain extra-terminal domain, is found on bromodomain proteins that play key roles in development, cancer progression and virus-host pathogenesis. It interacts with NSD3, JMJD6, CHD4, GLTSCR1, and ATAD5 all of which are shown to impart a pTEFb-independent transcriptional activation function on the bromodomain proteins [1].

1: The Brd4 extraterminal domain confers transcription activation independent of pTEFb by recruiting multiple proteins, including NSD3. Rahman S, Sowa ME, Ottinger M, Smith JA, Shi Y, Harper JW, Howley PM; Mol Cell Biol. 2011;31:2641-2652. PMID:21555454