Inhibits NF-kappa-B by complexing with and trapping it in the cytoplasm. Inhibits DNA-binding of NF-kappa-B p50-p65 and p50-c-Rel complexes.
Subcellular locations: Cytoplasm
Highly expressed in spleen, testis and lung, followed by kidney, pancreas, heart, placenta and brain. Also expressed in granulocytes and macrophages.