Negative elongation factor C/D is a protein that in humans is encoded by the TH1L gene.

The NELF complex of proteins interacts with the DSIF protein complex to repress transcriptional elongation by RNA polymerase II. The protein encoded by this gene is an essential part of the NELF complex. Alternative translation initiation site usage results in the formation of two isoforms with different N-termini. [provided by RefSeq, Jul 2008]. Publication Note: This RefSeq record includes a subset of the publications that are available for this gene. Please see the Gene record to access additional publications.
Function: Essential component of the NELF complex, a complex that negatively regulates the elongation of transcription by RNA polymerase II. The NELF complex, which acts via an association with the DSIF complex and causes transcriptional pausing, is counteracted by the P-TEFb kinase complex.