Acts as a Mg(2+) transporter. Can also transport other divalent cations such as Ba(2+), Sr(2+) and Fe(2+) but to a much less extent than Mg(2+) (By similarity). May be a receptor for ligands (trioxilins A3 and B3) from the hepoxilin pathway (PubMed:15317751). . This is the function of ENSG00000172548 (NIPAL4, NIPA like domain containing 4).