May function as a ferroxidase for ferrous (II) to ferric ion (III) conversion and may be involved in copper transport and homeostasis. Implicated in iron homeostasis and may mediate iron efflux associated to ferroportin 1. Binds 6 Cu cations per monomer. Detected in breast, colon, bone trabecular cells and fibroblasts. Belongs to the multicopper oxidase family. Extended N-terminus. Extended N-terminus. Extended N-terminus. Hephaestin entry