Tangier disease is caused by mutations in ATP binding cassette transporter A1( ABCA1). ABCA1 interacts with lipid-free apolip oproteins, promoting phospholipid and cholesterol efflux from cells and giving r ise to HDL particles. ABCA1 may act as a phospholipid translocase facilitating p hospholipid binding to apoA-I. ABCA1 gene expression is upregulated in cholester ol-loaded cells as a result of activation of LXR/RXR-mediated gene transcription . LXR and RXR coordinately induce a battery of genes mediating cellular choleste rol efflux, centripetal cholesterol transport, and cholesterol excret...