Major iron transporter that plays a key role in balancing cellular and systemic iron levels (By similarity). Transports iron from intestinal, splenic, and hepatic cells into the blood to provide iron to other tissues (By similarity). Controls therefore dietary iron uptake, iron recycling by macrophages, and release of iron stores in hepatocytes (By similarity). When iron is in excess, hepcidin/HAMP levels increase resulting in a degradation of ferroportin/SLC40A1 limiting the iron efflux to plasma (By similarity). Fe(2+)(in) = Fe(2+)(out) During elevated serum iron levels, liver-derived hepcidin/HAMP negatively regulates cell surface ferroportin/SLC40A1 by inducing its ubiquitination, internalization, and degradation. Indeed, hepcidin/HAMP affinity towards ferroportin/SLC40A1 increases by 80-fold in the presence of iron. Identified in a complex with STOM. Interacts with HAMP; this interaction promotes SLC40A1 rapid ubiquitination. Localized to the basolateral membrane of polarized epithelial cells. Belongs to the ferroportin (FP) (TC 2.A.100) family. SLC40A subfamily.