Apolipoprotein M (apoM) is a newly characterized human apolipoprotein that is mainly associated with high-density lipoprotein (HDL) in plasma and for a small proportion with triglyceride-rich lipoproteins (TGRLP) and low-density lipoproteins (LDL). ApoM fulfills the criteria of an HDL-associated apolipoprotein since the majority of apoM in plasma is associated with HDL. [...]