This gene encodes a protein which is found in the 7SK snRNP (small nuclear ribonucleoprotein). This snRNP complex inhibits a cyclin-dependent kinase, positive transcription elongation factor b, which is required for paused RNA polymerase II at a promoter to begin transcription elongation. A pseudogene of this gene is located on chromosome 3. Alternative splicing results in multiple transcript variants. [provided by RefSeq, May 2012]