Enables protein heterodimerization activity. Contributes to cholesterol transfer activity. Involved in cholesterol efflux and excretion. Acts upstream of or within cholesterol homeostasis and phospholipid transport. Located in apical plasma membrane. Is integral component of plasma membrane. Part of receptor complex. Is expressed in several structures, including Peyer's patch; alimentary system; brain; liver and biliary system; and thymus. Used to study sitosterolemia. Human ortholog(s) of this gene implicated in arteriosclerosis; familial hyperlipidemia; gallbladder disease; obesity; and sitosterolemia. Orthologous to human ABCG8 (ATP binding cassette subfamily G member 8). [provided by Alliance of Genome Resources, Apr 2022]