The non-coding RNA (ncRNA) 7SK has a central role in controlling transcription in embryonic stem cells.7SK is required for the repression of genes that are silent or expressed at a low level. Widespread failed transcriptional termination was also seen after 7SK knockdown. 7SK is a major regulator of transcriptional directionality, by preventing the transcription of upstream divergent RNAs (udRNAs).
Castelo-Branco et al. Genome Biology 2013 14:R98 doi:10.1186/gb-2013-14-9-r98