BET bromodomain

Class

BET bromodomain inhibitor

The BET (bromodomain and extra-terminal domain) family comprises four related proteins—BRD2, BRD3, BRD4, and the testis-restricted BRDT—that function as epigenetic 'readers.' Each contains two tandem bromodomains, called BD1 and BD2, which recognize and bind acetylated lysine residues on histone tails, the protein spools around which DNA is wound. By docking onto these acetylated marks, BET proteins act as scaffolds that recruit transcription-elongation machinery to gene promoters and enhancers, thereby sustaining expression of genes involved in cell proliferation, inflammation, and lipid metabolism. Because BET proteins govern such broad transcriptional programs, they have been explored as drug targets in cancers driven by oncogenes such as MYC, in inflammatory conditions, and in cardiometabolic and renal disease, where they influence genes controlling lipoprotein handling and vascular inflammation. Pan-BET inhibitors that block both bromodomains suppress these programs broadly but can also affect normal blood cell production and gut lining maintenance, since these tissues rely on the same transcriptional machinery. This has driven interest in selectively targeting one bromodomain, particularly BD2, to preserve therapeutic gene-regulatory effects while reducing mechanism-based toxicity.