BET proteins

Class

BET protein inhibitor

BET proteins—BRD2, BRD3, BRD4, and the testis-restricted BRDT—are a family of 'reader' proteins that recognize acetylated lysine residues on histone tails, a chemical mark associated with active gene transcription. By binding these marks through paired protein modules called bromodomains, BET proteins recruit transcriptional machinery to specific genes, sustaining the expression of genes governing cell growth, inflammation, and lipid metabolism. Because several disease-relevant genes—including growth-promoting oncogenes and genes that regulate cholesterol handling and inflammatory signaling—depend heavily on BET-mediated transcription, blocking the bromodomain pocket with a small molecule can reduce output from these gene programs. This rationale has been explored across oncology, where certain cancers depend on BET-sustained expression of growth-driving genes, and in cardiometabolic and inflammatory disease, where BET activity influences lipoprotein production and vascular inflammation. Different BET inhibitors vary in which bromodomains they preferentially engage, which shapes their gene-expression footprint and their side-effect profile, since BET proteins are expressed broadly across tissues rather than restricted to diseased cells. This mechanism therefore represents a strategy of modulating gene transcription indirectly, by removing a reader protein from chromatin rather than acting on a single gene product.