Werner syndrome ATP dependent helicase (WRN) ,also named as RECQ3 or RecQ protein like 2, is a 1432 amino acid protein, which contains one HRDC domain, one helicase C-terminal domain, one helicase ATP-binding domain and 3'-5' exonuclease domain. WRN localizes in the nucleoplasm and belongs to the helicase family. WRN plays a central role in the repair of methylation-induced DNA damage and has an helicase activity necessary to prevent dramatic telomere loss during DNA replication. WRN gene mutation has an association with Werner syndrome and colorectal cancer.