This gene encodes a member of the peptidase C65 family of ubiquitin isopeptidases. Members of this family remove ubiquitin from proteins. The encoded enzyme specifically recognizes and removes M1(Met1)-linked, or linear, ubiquitin chains from protein substrates. Linear ubiquitin chains are known to regulate the NF-kappa B signaling pathway in the context of immunity and inflammation. Mutations in this gene cause a potentially fatal autoinflammatory syndrome in human patients. [provided by RefSeq, Sep 2016].