The function of ABCG1 (ATP binding cassette subfamily G member 1, Ensembl gene identifier ENSG00000160179) is as follows. Catalyzes the efflux of phospholipids such as sphingomyelin, cholesterol and its oxygenated derivatives like 7beta- hydroxycholesterol and this transport is coupled to hydrolysis of ATP (PubMed:17408620, PubMed:24576892). The lipid efflux is ALB-dependent (PubMed:16702602). Is an active component of the macrophage lipid export complex. Could also be involved in intracellular lipid transport processes. The role in cellular lipid homeostasis may not be limited to macrophages. Prevents cell death by transporting cytotoxic 7beta- hydroxycholesterol (PubMed:17408620). {ECO:0000269|PubMed:16702602, ECO:0000269|PubMed:17408620, ECO:0000269|PubMed:24576892}.