Involved in the transfer of neutral lipids, including cholesteryl ester and triglyceride, among lipoprotein particles. Allows the net movement of cholesteryl ester from high density lipoproteins/HDL to triglyceride-rich very low density lipoproteins/VLDL, and the equimolar transport of triglyceride from VLDL to HDL (PubMed:24293641). Regulates the reverse cholesterol transport, by which excess cholesterol is removed from peripheral tissues and returned to the liver for elimination (By similarity). cholesteryl (9Z-octadecenoate)(in) = cholesteryl (9Z-octadecenoate)(out) 1,2,3-tri-(9Z-octadecenoyl)-glycerol(in) = 1,2,3-tri-(9Z-octadecenoyl)-glycerol(out) cholesteryl (9Z,12Z)-octadecadienoate(in) = cholesteryl (9Z,12Z)-octadecadienoate(out) Secreted in plasma. Expressed by the liver. Belongs to the BPI/LBP/Plunc superfamily. BPI/LBP family.