May modulate activity of cullin-RING E3 ubiquitin ligase (CRL) complexes (PubMed:21778237). May down-regulate activation of NF-kappa-B (PubMed:15799966). Interacts (via COMM domain) with COMMD1 (via COMM domain) (PubMed:15799966). Interacts with RELA, RELB, NFKB1/p105, NFKB2/p100. Interacts with CCDC22, CCDC93, SCNN1B, CUL3, CUL4B, CUL5, CUL7 (PubMed:28892079, PubMed:15799966, PubMed:21778237, PubMed:23563313, PubMed:23637203, PubMed:25355947). Ubiquitous.