Low-density lipoprotein (LDL) refers to a class and range of lipoprotein particles, varying somewhat in their size and contents, which carry cholesterol in the blood and around the body, for use by various cells.It is the final stage of VLDL (very low-density lipoprotein)witch is produced by the liver. The LDL contains the apoprotein B-100 (Apo B-100) among is plasma lipids. It is commonly referred to as "bad cholesterol" due to the link between high LDL levels and cardiovascular disease.