It has been confirmed that ApoM is required for pre-β- HDL formation and cholesterol efflux to HDL, and that it protects against atherosclerosis.4 ApoM increased formation ofpre-β-HDL particles and had a profoundly protective effect on atherosclerotic lesion formation in hypercholesterolaemic Ldlr-/- mice.4 Atherosclerotic lesion areas in aortic roots and the thoracic aorta were reduced in Ldlr-/- mice infected with Ad-ApoM.4 This evidence concerns the gene APOM and atherosclerosis.