Ferroportin (SLC40A1) is an iron transporter suggested to play roles in intestinal iron absorption and cellular iron release. To date, Ferroportin is the only known mammalian iron exporter and is essential for transport of iron from one cell type to another.nFerroportin has 9-12 transmembrane domains. The topology of the transporter has not been defined with precision and the number of transmembrane domains is still under scrutiny. Studies indicate that the amino terminus of Ferroportin is cytosolic. The location of the carboxyl-terminal, however, is unclear. A second controversial issue regarding Ferroportin structure is whether Ferroportin is a monomer or dimer. Many reports using similar approaches including chromatography, cross-linking and physical techniques such as birefringence, have led to contrasting results.nFerroportin is found in all the tissues where major iron flows are regulated, including duodenal enterocytes, placental trophoblast, macrophages, and hepatocytes