Transferrin Receptor 2 (TFR2) is a type II transmembrane glycoprotein that plays a crucial role in iron homeostasis. It is highly homologous to Transferrin Receptor 1 (TFR1) and is primarily expressed in the liver and erythroid precursor cells. TFR2 is involved in the regulation of hepcidin, a hormone that controls iron absorption and distribution in the body. It helps mediate the cellular uptake of iron-bound transferrin, although its affinity for iron is lower than that of TFR1 (PMID: 24658816). It is more involved in sensing iron levels and regulating hepcidin expression rather than direct iron uptake. TFR2 is predominantly expressed in hepatocytes (liver cells) and erythroid precursors (cells that give rise to red blood cells). It is also found in the enterocytes of the small intestine (PMID: 29969719). In the liver, TFR2 acts as a sensor for circulating iron-bound transferrin and helps regulate hepcidin production. Hepcidin, in turn, controls iron absorption from the diet and iron release from macrophages. The molecular weight of TFR2 is 88 kDa, its observed molecular weight is 88-97 kDa.