Serotransferrin belongs to transferrin family, and contains 2 transferrin-like domains. The protein is a secreted protein, and expressed by the liver and secreted in plasma. Transferrins are iron binding transport proteins which can bind two Fe3+ ions in association with the binding of an anion. It is responsible for the transport of iron from sites of absorption and heme degradation to those of storage and utilization. Serum transferrin may also have a further role in stimulating cell proliferation.