ABCG8 is a symbol for the gene, ATP binding cassette subfamily G member 8, in humans. Other names include: ATP-binding cassette sub-family G member 8; Sterolin-2; gallbladder disease 4; sterolin 2; ATP-binding cassette, sub-family G (WHITE), member 8; GBD4. The encoded protein has an amino acid length of 673 and a mass of 75.7 kDa. Other isoforms may exist. ABCG8 is a member of the ABC transporter superfamily, ABCG family, Eye pigment precursor importer (TC 3.A.1.204) subfamily. This gene shares homology with other species, including: Mouse, Rat, Zebrafish, Frog, Chicken.