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 transporter is a member of the MRP subfamily which is involved in multi-drug resistance. Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, Jul 2008]