Transferrins are iron-binding blood plasma glycoproteins that control the level of free iron in biological fluids. In humans, it is encoded by the TF gene. Transferrin is a glycoprotein that binds iron very tightly but reversibly. Although iron bound to transferrin is less than 0.1 % (4 mg) of the total body iron, it is the most important iron pool, with the highest rate of turnover (25 mg/24 h). Transferrin has a molecular weight of around 80 kDa and contains 2 specific high-affinity Fe(III) binding sites. Description: Normal serum. Alternative Names: Serotransferrin precursor protein, PRO1400 protein, beta 1 metal binding globulin protein, Apotransferrin protein, DKFZp781D0156 protein, TF protein, Siderophilin protein, PRO2086 protein, PRO1557 protein