The function of Ensembl gene identifier ENSG00000008283 (CYB561, cytochrome b561) is as follows. Transmembrane reductase that probably uses ascorbate as an electron donor to reduce Fe(3+) into Fe(2+) and could play a role in iron transport. It is also able to reduce extracellular monodehydro-L- ascorbate and could be involved in the regeneration and homeostasis within secretory vesicles of ascorbate which in turn provides reducing equivalents needed to support the activity of intravesicular enzymes. .