TARDBP (UniProt/Swiss-Prot entry Q13148) is a DNA and RNA-binding protein which regulates transcription and splicing. It binds to the chromosomally integrated TAR DNA from HIV-1 thereby repressing HIV-1 transcription. TARDBP is also involved in the regulation of CFTR splicing where it promotes CFTR exon 9 skipping. The resulting aberrant splicing is associated with pathological features typical of cystic fibrosis.