NELF-B is an essential component of the NELF complex, a complex that negatively regulates the elongation of transcription by RNApolymerase II. The NELF complex causes transcriptional pausing and is counteracted by the P-TEFb kinase complex. It may be able toinduce chromatin unfolding. NELF-B is a modulator of ligand dependent and independent expression of estrogen receptor-α target genes.NELF-B expression is reduced in metastatic and recurrent breast cancer, suggesting that low levels of NELF-B in breast cancers may serveas an indicator for poor prognosis.
