ApoM is a 25 kDa plasma protein associated with high-density lipoproteins (HDLs). ApoM is important in the formation of pre-ss-HDL and also in increasing cholesterol efflux from macrophage foam cells. Lipoproteins consist of lipids solubilized by apolipoproteins. ApoM lacks an external amphipathic motif and is uniquely secreted to plasma without cleavage of its terminal signal peptide.
Jiyao W et al.(2023). "The conserved domain database in 2023.",