SPT16 and SSRP1 are found in all eurkaryotic cells and exists as part of an essential heterodimer complex. Together, SPT16 and SSRP1 are a highly abundant nuclear complex that in mammals has been called FACT, or Facilitates Chromatin Transcription. FACT enhances the processivity of RNA polymerase II through nucleosomes. Evidence also points to a role for FACT in replication, possibly by enhancing DNA polymerase through nucleosomes as well.Synonyms: Chromatin-specific transcription elongation factor 140 kDa subunit, FACT 140 kDa subunit, FACT complex subunit SPT16, FACTp140, Facilitates chromatin transcription complex subunit SPT16