Initiating RNA polymerase II and TIPs as hallmarks of enhancer activity and tissue-specificity

In past years, many efforts were invested to define epigenetic features associated with enhancers of transcription. We propose that both transcription initiation and the H3K4me3 histone modification are among the best hallmarks of active enhancers in several primary tissues and extend the concept of large transcription initiation platforms (TIPs).