Background：CD71, also known as transferrin receptor protein 1(TfR1), is a transmembrane glycoprotein composed of two disulfide-linked monomers, each of 90 kDa molecular weight. Each monomer binds one holo-transferrin molecule creating an iron-Tf-TfR complex which enters the cell by endocytosis. CD71 is present on actively proliferating cells and is essential for iron transport into proliferating cells.
