BRD4 Targeted Library
BRD4 is a transcriptional and epigenetic regulator that plays a pivotal role during embryogenesis and cancer development. As the other members of the Bromodomains and Extraterminal (BET) family BRD4 is characterized by two tandem bromodomains (BD1, BD2). BDs bind acetylated lysine residues on target proteins, including histones. Being their affinity higher for proteins with multiple acetylated residues, BRD4 and the other BET proteins, interact with hyper-acetylated histone regions along the chromatin, accumulating on transcriptionally active regulatory elements and promoting gene transcription both at initiation and elongation step.
BRD4 was first identified as a cell cycle controlling protein, which associates with chromosomes during mitosis to mark genes whose ready transcription in G1 is required to ensure cell cycle progression. The transcriptional activity of BRD4 is essential during embryogenesis and for cell identity determination. Inhibiting Brd4 expression leads to preventing cancer development, that is why Brd4 as a promising anticancer drug target. 
 B. Donati, E. Lorenzini, and A. Ciarrocchi, “BRD4 and Cancer: Going beyond transcriptional regulation,” Mol. Cancer, vol. 17, no. 1, pp. 1–13, 2018, doi: 10.1186/s12943-018-0915-9.