This gene encodes a member of the TFB4 family. The encoded protein is a subunit of the core-TFIIH basal transcription factor and localizes to the nucleus. The encoded protein is involved in RNA transcription by RNA polymerase II and nucleotide excision repair and associates with the Cdk-activating kinase complex. Alternative splicing results in multiple transcript variants. A related pseudogene has been identified on chromosome 14. [provided by RefSeq, Dec 2012].