DEAD-box proteins, characterized by the conserved motif Asp-Glu-Ala-Asp, are putative RNA helicases implicated in several cellular processes involving modifications of RNA secondary structure and ribosome/spliceosome assembly. Based on their distribution patterns, some members of this family may be involved in embryogenesis, spermatogenesis and cellular growth and division. DDX43 (DEAD (Asp-Glu-Ala-Asp) box polypeptide 43), also known as CT13 or HAGE, is a 648 amino acid protein that contains one KH domain, one helicase C-terminal domain and one helicase ATP-binding domain and belongs to the DEAD-box family. Expressed in testis and present at abnormally high levels in a variety of tumors, DDX43 is thought to function as an ATP-dependent RNA helicase that may play a role tumor transformation and metastasis.