WRN is a member of the RecQ Helicase family. It is the only RecQ Helicase that contains 3' to 5' exonuclease activity. These exonuclease activities include degradation of recessed 3' ends and initiation of DNA degradation from a gap in dsDNA. WRN is important in repair of double strand breaks by homologous recombination or non-homologous end joining, repair of single nucleotide damages by base excision repair, and is effective in replication arrest recovery. WRN may also be important in telomere maintenance and replication, especially the replication of the G-rich sequences.