Acts upstream of or within I-kappaB kinase/NF-kappaB signaling. Located in cytosol and nucleus. Is expressed in embryo; eye; and heart. Human ortholog(s) of this gene implicated in rheumatoid arthritis. Orthologous to human NFKBIL1 (NFKB inhibitor like 1). [provided by Alliance of Genome Resources, Apr 2022]