BRD4 and colorectal carcinoma: Bromodomain-containing protein 4 (BRD4) mediates its role as transcriptional co-activator by acting both as a passive scaffold to promote recruitment of transcription factors and as an active kinase to phosphorylate RNA polymerase II, thereby regulating transcription.474 Upregulated expression of transcriptional regulator BRD4 is frequently observed in CRC.