Deubiquitinase involved in innate antiviral immunity by mediating deubiquitination of CGAS and DDX58/RIG-I (PubMed:31534008, PubMed:32027733). Negatively regulates DDX58/RIG-I by mediating 'Lys-63'-linked deubiquitination of DDX58/RIG-I, inhibiting type I interferon signaling (PubMed:32027733). Also regulates 'Lys-63'-linked ubiquitination level of MDA5/IFIH1 (PubMed:32027733). Acts as a positive regulator of the cGAS-STING pathway by catalyzing 'Lys-48'-linked deubiquitination of CGAS, thereby promoting its stabilization (PubMed:31534008). Can reduce the levels of BCL2L11/BIM ubiquitination and stabilize BCL2L11 in response to the RAF-MAPK-degradation signal (By similarity). By acting on BCL2L11 levels, may counteract the anti-apoptotic effects of MAPK activity (By similarity). Thiol-dependent hydrolysis of ester, thioester, amide, peptide and isopeptide bonds formed by the C-terminal Gly of ubiquitin (a 76-residue protein attached to proteins as an intracellular targeting signal). Interacts with phosphorylated BCL2L11 isoform BIMEL; this interaction leads to BCL2L11 deubiquitination and stabilization. The disease is caused by variants affecting the gene represented in this entry. Belongs to the peptidase C19 family. Although strongly related to USP22, which deubiquitinates histones, lacks the N-terminal UBP-type zinc finger, suggesting it does not have the ability to deubiquitinate histones.