Transferrin (TF) is a secreted protein belonging to the transferrin family that is expressed by the liver and secreted into the plasma. TF has a molecular weight of about 80kDa and contains two specific high-affinity Fe3+ binding sites. TFs is an iron-binding glycoprotein present in plasma that regulates the level of free iron in biological fluids. Its main role is to transport iron from duodenal absorption centers and leukocyte macrophages to other tissues. TF is related to the innate immune system. In an inflammatory state, its levels are reduced. It is common to see increased plasma TF levels in patients with iron deficiency anemia. Plasma TF levels are generally reduced in patients with iron overload and protein malnutrition. Recently, TF and its receptors have been found to reduce tumor cells when TF receptors attract antibodies. TF is an acute phase protein, so its levels are decreased in inflammation, cancer, and certain diseases.