BRD4 and cancer: The double life of KLF5 promoter region interacts with enhancer and transcription start site of colon cancer-associated transcription 1 gene, with heterologous deletion impairs cancer stem identity, bromodomain containing 4 and other cofactors participates in a core regulatory pathway, constructing a three-dimension structure (promoter, enhancer and transcription start sites), which plays opposing roles in regulating gene expression, cellular function, and transformation [117].