DDX19B is an ATP-dependent DEAD-box RNA helicase that functions as a ribonucleoprotein remodeler rather than a classical RNA unwinder 1. During mRNA export through the nuclear pore complex, DDX19B dissociates nuclear RNA-binding proteins from mRNPs and facilitates their replacement by cytoplasmic mRNA-binding proteins 1. This process requires coordinated activation by Gle1 and Nup42 at the cytoplasmic face of the NPC 2. DDX19B function is fine-tuned by SUMOylation at lysine 26, which enhances its interaction with Gle1 and is essential for complete mRNA export activity 3. Beyond nuclear export, DDX19B regulates perinuclear translation by tethering the translation initiation factor CTIF, preventing uncontrolled cytoplasmic translation and dysregulation of nonsense-mediated mRNA decay 4. Clinically, DDX19B expression modulates selinexor sensitivity in leukemia by regulating MCL1 mRNA export, suggesting potential as a biomarker for XPO1 inhibitor therapy 5. As a member of the DEAD-box helicase family, DDX19B contributes to genome stability 6, and altered DDX19B expression has been implicated in hepatocellular carcinoma prognosis 7.