Mutations in the ABCA1 gene (ATP-binding cassette transporter 1) are associated with Tangier disease (TD). TD is an autosomal recessive disorder resulting from an absence of plasma HDL, cholesterol ester depositing in the reticulo-endothelial system and disorders in cellular lipid trafficking. It is expressed on the plasma membrane and the Golgi complex and is regulated by cholesterol flux. Regulation of the cholesterol flux between HDL and macrophages is competitive between ABCA1 and SR-BI. Species Human. Other species not tested.