The function of COMMD4 (COMM domain containing 4, ENSG00000140365) is as follows. Scaffold protein in the commander complex that is essential for endosomal recycling of transmembrane cargos; the commander complex is composed of the CCC subcomplex and the retriever subcomplex (PubMed:37172566, PubMed:38459129). May modulate activity of cullin- RING E3 ubiquitin ligase (CRL) complexes (PubMed:21778237). Down- regulates activation of NF-kappa-B (PubMed:23637203). {ECO:0000269|PubMed:15799966, ECO:0000269|PubMed:37172566, ECO:0000269|PubMed:38459129, ECO:0000305|PubMed:21778237}.