Deubiquitinase that specifically removes linear ('Met-1'- linked) polyubiquitin chains to substrates and acts as a regulator of angiogenesis and innate immune response (PubMed:23708998, PubMed:23746843, PubMed:23806334, PubMed:23827681, PubMed:24726323, PubMed:24726327, PubMed:26997266, PubMed:27523608, PubMed:27559085, PubMed:28919039, PubMed:30804083, PubMed:35170849, PubMed:35587511, PubMed:38630025, PubMed:38652464). Required during angiogenesis, craniofacial and neuronal development by regulating the canonical Wnt signaling together with the LUBAC complex (PubMed:23708998). Acts as a negative regulator of NF-kappa-B by regulating the activity of the LUBAC complex (PubMed:23746843, PubMed:23806334). OTULIN function is mainly restricted to homeostasis of the LUBAC complex: acts by removing 'Met-1'-linked autoubiquitination of the LUBAC complex, thereby preventing inactivation of the LUBAC complex (PubMed:26670046). Acts as a key negative regulator of inflammation by restricting spontaneous inflammation and maintaining immune homeostasis (PubMed:27523608). In myeloid cell, required to prevent unwarranted secretion of cytokines leading to inflammation and autoimmunity by restricting linear polyubiquitin formation (PubMed:27523608). Plays a role in innate immune response by restricting linear polyubiquitin formation on LUBAC complex in response to NOD2 stimulation, probably to limit NOD2- dependent pro-inflammatory signaling (PubMed:23806334). {ECO:0000269|PubMed:23708998, ECO:0000269|PubMed:23746843, ECO:0000269|PubMed:23806334, ECO:0000269|PubMed:23827681, ECO:0000269|PubMed:24726323, ECO:0000269|PubMed:24726327, ECO:0000269|PubMed:26670046, ECO:0000269|PubMed:26997266, ECO:0000269|PubMed:27523608, ECO:0000269|PubMed:27559085, ECO:0000269|PubMed:28919039, ECO:0000269|PubMed:30804083, ECO:0000269|PubMed:35170849, ECO:0000269|PubMed:35587511, ECO:0000269|PubMed:38630025, ECO:0000269|PubMed:38652464}. This is the function of Ensembl gene identifier ENSG00000154124 (OTULIN, OTU deubiquitinase with linear linkage specificity).