protein low-density lipoprotein PMID:28870972 beta-lipoproteins LDL PMID:28859941 PMID:28792690 Wikipedia:Low-density_lipoprotein PMID:11082530 chebi_ontology low-density lipoproteins PMID:28432662 PMID:15913955 A class of lipoproteins of small size (18-25 nm) and low density (1.019-1.063 g/ml) particles with a core composed mainly of cholesterol esters and smaller amounts of triglycerides. The surface monolayer consists mostly of phospholipids, a single copy of apolipoprotein B-100, and free cholesterol molecules. The main function of LDL is to transport cholesterol and cholesterol esters from the liver. Excessive levels are associated with cardiovascular disease. PMID:19349632 CHEBI:39026 PMID:15583011 PMID:28847800 PMID:28827781 PMID:28401639