Predicted to enable ISG15-specific protease activity; cysteine-type endopeptidase activity; and thiol-dependent deubiquitinase. Predicted to be involved in negative regulation of type I interferon-mediated signaling pathway; protein deubiquitination; and regulation of inflammatory response. Predicted to act upstream of or within response to bacterium and response to stilbenoid. Predicted to be located in intracellular membrane-bounded organelle. Predicted to be active in cytosol and nucleus. Orthologous to several human genes including USP18 (ubiquitin specific peptidase 18). [provided by Alliance of Genome Resources, Apr 2022]