背景资料：The protein encoded by this gene is included in 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, White). This protein is a member of the White subfamily and is expressed predominantly in liver tissue. The function has not yet been determined but may involve cholesterol transport. Alternate splice variants have been described but their full length sequences have not been determined.