Probable ATP-dependent RNA helicase (By similarity). Plays a role in ribosome biogenesis and TP53/p53 regulation through its interaction with NPM1 (PubMed:23019224). ATP + H2O = ADP + H(+) + phosphate Interacts with NPM1; this interaction prevents interaction between NPM1 and HDM2. Colocalized with NPM1 in the nucleoli. Weakly or undetectably expressed in normal organs. Up-regulated in renal cell carcinoma. Belongs to the DEAD box helicase family. DDX31/DBP7 subfamily.