The function of Ensembl gene identifier ENSG00000123191 (ATP7B, ATPase copper transporting beta) is as follows. Copper ion transmembrane transporter involved in the export of copper out of the cells. It is involved in copper homeostasis in the liver, where it ensures the efflux of copper from hepatocytes into the bile in response to copper overload. {ECO:0000269|PubMed:18203200, ECO:0000269|PubMed:22240481, ECO:0000269|PubMed:24706876, ECO:0000269|PubMed:26004889}.