Predicted to enable several functions, including cation binding activity; cholesterol binding activity; and cholesterol transfer activity. Involved in innate immune response in mucosa. Acts upstream of or within regulation of intestinal cholesterol absorption and response to stilbenoid. Located in extracellular space. Is expressed in embryo and liver. Human ortholog(s) of this gene implicated in Alzheimer's disease; colitis; myocardial infarction; and ulcerative colitis. Orthologous to human APOA4 (apolipoprotein A4). [provided by Alliance of Genome Resources, Apr 2022]