The function of Ensembl gene identifier ENSG00000140450 (ARRDC4, arrestin domain containing 4) is as follows. Functions as an adapter recruiting ubiquitin-protein ligases to their specific substrates (By similarity). Plays a role in endocytosis of activated G protein-coupled receptors (GPCRs) (Probable). Through an ubiquitination-dependent mechanism also plays a role in the incorporation of SLC11A2 into extracellular vesicles (By similarity). May play a role in glucose uptake (PubMed:19605364). Participates in innate immune response by promoting IFIH1/MDA5 activation through interaction with TRIM65 (PubMed:28594402). {ECO:0000250|UniProtKB:A0A0B4J1F4, ECO:0000269|PubMed:19605364, ECO:0000269|PubMed:28594402, ECO:0000305}.