ABCA1 is an ATP-binding cassette transporter that catalyzes ATP-dependent translocation of phospholipids and cholesterol across cellular membranes 12. It preferentially transports phosphatidylcholine and mediates cholesterol efflux to lipid-poor apolipoproteins, facilitating nascent HDL particle formation through reverse cholesterol transport 31. Mechanistically, ABCA1 extracts lipids from the plasma membrane and extracellular domain and translocates them through a hydrophobic tunnel 2. ABCA1 expression is tightly regulated, including post-translational stabilization via K63-linked ubiquitination to counter lysosomal degradation 4. Loss-of-function ABCA1 mutations cause Tangier disease, characterized by severe HDL deficiency, macrophage cholesterol accumulation, and premature atherosclerosis 5. ABCA1 deficiency in glomerular endothelial cells exacerbates diabetic kidney disease through cholesterol accumulation, endoplasmic reticulum stress, and inflammation 6. Emerging evidence links ABCA1 to additional pathologies: genetic polymorphisms associate with hypertension risk 7, and upregulation promotes temozolomide chemoresistance in glioma while facilitating M2 macrophage infiltration 8. ABCA1 represents a therapeutic target, with PPAR and LXR agonists capable of enhancing its expression and stabilization to promote cholesterol efflux and reduce atherosclerotic progression 9.