NIPA2 is highly selective for Mg2+ transportation, other members of the family transport other cations as well. NIPA2 has 9 transmembrane protein domains. It is also found in the early endosome and transfers extracellular Mg2+ into the cytoplasm. NIPA2 is highly conserved among vertebrates; human and mouse NIPA2 have a 96% amino acid identity. NIPA2 is expressed in the heart, CNS and pancreas. Its expression is upregulated in MDCT cells cultured in low-magnesium levels compared to normal magnesium.