May serve to import iron into the mitochondria (By similarity). Important in metal transport, in particular iron. Involved in apical iron uptake into duodenal enterocytes. Involved in iron transport from acidified endosomes into the cytoplasm of erythroid precursor cells. May play an important role in hepatic iron accumulation and tissue iron distribution. Forms a complex with NDFIP1 and NEDD4L, in cortical neurons, in response to iron and colbalt exposure; this interaction leads to ubiquitination by NEDD4L and proteasome-dependent degradation. Interacts with NDFIP2. Interacts with COX2 and TOM6 at the outer mitochondrion membrane (By similarity). Interacts with ARRDC1; controls the incorporation of SLC11A2 into extracellular vesicles through an ubiquitination-dependent mechanism (By similarity). Interacts with ARRDC4; controls the incorporation of SLC11A2 into extracellular vesicles through an ubiquitination-dependent mechanism (PubMed:27462458). Also found in extracellular vesicles different from exosomes. Isoform 2 is abundantly expressed in erythroid precursor cells (at protein level). Expressed at low levels in most tissues analyzed. Expressed at low levels in small intestine and at higher levels in kidney. Up-regulated under iron-depletion conditions in the proximal portion of the duodenum where it is abundantly expressed in the brush border of absorptive epithelial cells (at protein level). N-glycosylated. Ubiquitinated by WWP2. Defects in Slc11a2 are the cause of microcytic anemia (mk). Homozygous mk/mk mice have hypochromic microcytic anemia due to severe defects in intestinal iron absorption and erythroid iron utilization. Mice display no apparent anatomical abnormalities. They are however anemic, show progressive postnatal growth retardation, and at birth have elevated liver iron stores compared with wild-type littermates. None survive for more than 7 days. Heterozygotes appear normal, showing no significant hematological abnormalities. However, by 8 weeks, their liver iron content is lower than in wild-type littermates. Nifedipine induces duodenal iron accumulation and mobilizes iron from the liver of iron-overloaded mice. Belongs to the NRAMP family.