Background: The 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 are divided into seven distinct subfamilies (ABC1, MDR/TAP, MRP, ALD, OABP, GCN20, and White). This ABC full-transporter is a member of the MRP subfamily which is involved in multi-drug resistance. Multiple transcript variants encoding different isoforms have been found for this gene.