Enables cholesterol transfer activity. Involved in several processes, including animal organ regeneration; response to estrogen; and response to glucocorticoid. Predicted to be located in extracellular space. Predicted to be part of chylomicron; spherical high-density lipoprotein particle; and very-low-density lipoprotein particle. Biomarker of hyperthyroidism. Human ortholog(s) of this gene implicated in familial hypercholesterolemia. Orthologous to human APOA2 (apolipoprotein A2). [provided by Alliance of Genome Resources, Apr 2022]