[Isoform 1]: Catalyzes ATP-dependent import of organic anions such as taurocholate and estrone sulfate (PubMed:12379217). In vitro, also imports ochratoxin A (PubMed:12379217). Also mediates cholesterol efflux independent of apolipoprotein, and plays a role in sphingomyelin production in oligodendrocytes (PubMed:23560799). . [Isoform 3]: Catalyzes ATP-dependent efflux of cholesterol and taurocholate (PubMed:29300488). Interaction with ABCA1 potentiates cholesterol efflux to lipid-free APOA1, which regulates high-density lipoprotein cholesterol levels (PubMed:28882873). . This is the function of ENSG00000141338 (ABCA8, ATP binding cassette subfamily A member 8).