DDX4 (DEAD (Asp-Glu-Ala-Asp) box polypeptide 4) is under DEAD box helicase family. DEAD box proteins, characterized by two domains, i.e., ATP-binding and C-terminal helicase domain. It is made up of 724 amino acids. DDX4 is also involved in embryogenesis, spermatogenesis, and cellular growth and division. DDX4 also plays a role in germ cell development and sperm motility. It has 4 isoforms due to alternative splicing. DDX4 is specifically expressed in the germ cell lineage in both sexes and functions in germ cell development.