The membrane-associated protein encoded by this gene is a member of the superfamily of ATP-binding cassette (ABC)transporters. ABC proteins transport various molecules across extra- and intra-cellular membranes. ABC genes aredivided into seven distinct subfamilies (ABC1, MDR/TAP, MRP, ALD, OABP, GCN20, White). This protein is a member of theMDR/TAP subfamily. Members of the MDR/TAP subfamily are involved in multidrug resistance as well as antigenpresentation. This gene encodes a half-transporter involved in the transport of heme from the mitochondria to thecytosol. With iron/sulfur cluster precursors as its substrates, this protein may play a role in metal homeostasis.Mutations in this gene have been implicated in X-linked sideroblastic anemia with ataxia. (provided by RefSeq)