Macrophage-specific antiporter that fluxes metal ions in either direction against a proton gradient. Localized to late endosomal lysosomal membranes, delivers bivalent cations from the cytosol into these acidic compartments where they may directly affect antimicrobial activity (PubMed:11237855). Involved in iron metabolism and host natural resistance to infection with intracellular parasites. Pathogen resistance involves sequestration of Fe(2+) and Mn(2+), cofactors of both prokaryotic and eukaryotic catalases and superoxide dismutases, not only to protect the macrophage against its own generation of reactive oxygen species, but to deny the cations to the pathogen for synthesis of its protective enzymes (Probable). {ECO:0000269|PubMed:11237855, ECO:0000305|PubMed:16103355, ECO:0000305|PubMed:16395392}. This is the function of Ensembl gene identifier ENSG00000018280 (SLC11A1, solute carrier family 11 member 1).