This gene encodes a member of the ATP-binding cassette superfamily of transporters. ATP-binding cassette proteins transport various molecules across extra- and intra-cellular membranes. The encoded protein is localized to the mitochondrial inner membrane where it interacts with and stabilizes mitoferrin-1, and is important for heme biosynthesis. Additional evidence suggests the encoded protein is involved in oxidative stress protection and erythropoisesis. [provided by RefSeq, May 2013]