The function of this encoded protein is to transport iron from the intestine, reticuloendothelial system, and liver parenchymal cells to all proliferating cells in the body. In addition to its function in iron transport, this protein may also have a physiologic role as granulocyte/pollen binding protein (GPBP) involved in the removal of certain organic matter/allergins from serum. From the blood, transferrin is internalized by erythroblasts and reticulocytes upon binding the transferrin receptor (TfR), also designated CD71, through a system of coated pits and vesicles. After Fe release, transferrin is returned to the extracellular medium, where it can be reused.
