Bromodomain-containing protein (BRD4) plays a significant role in gene expression, both in normal and cancerous cells, by directly interacting with acetylated lysine residues at the N-terminal of histone tails with the help of transcription factors such as RELA, ER, and P53. In a healthy body, it promotes cell cycle regulation, cell growth, and development, and serves as a scaffold that controls the recruitment of other transcription regulators to the chromatin network. This ultimately modulates the transcription machinery itself. However, due to dysregulation of BRD4, changes occur in macromolecular complexes of DNA, which affects gene expression and epigenetic regulation and contributes to the pathogenesis of the disease.