Transferrins are eukaryotic iron-binding glycoproteins with the ability to bind ferric iron with high affinity in the cleft of each of two homologous lobes. They control the level of free iron in biological fluids [PMID: 3032619]. Members of the family include blood serotransferrin (siderophilin), milk lactotransferrin (lactoferrin), egg white ovotransferrin (conalbumin) and membrane-associated melanotransferrin. The iron-deficient transferrins inhibit the growth of certain bacteria and fungi by making iron unavailable for bacterial metabolism [PMID: 6452038].