The low-density lipoprotein (LDL) receptor (LDLR) is a chimeric protein consisting of 839 amino acids belonging to the LDLR gene family. It is a cell surface receptor that recognizes ApoB100 embedded on the phospholipid layer outside LDL particles and also recognizes ApoE proteins present in celiac remnants and VLDL remnants.LDLR mediates endocytosis of cholesterol-rich LDL.The LDLR complex is present on the cell surface of the lattice protein-coated follicles (or buds), which bind, via articulating proteins, LDL- cholesterol, de-assembles to form lattice protein-coated endosomal vesicles, which internalizes LDL-cholesterol during endocytosis and also prevents the diffusion of LDL at the membrane surface. The above process occurs in all nucleated cells, but mainly in the liver, where about 70% of LDL is removed by circulation. up-regulation of LDLR leads to a decrease in lipids, which may be associated with hyperthyroidism, whereas the opposite is true for hypothyroidism.