Zinc (Zn) transporter ZIP8, encoded by SLC39A8, is a unique transporter that can transport divalent manganese (Mn) and cadmium (Cd) in addition to Zn. Recently, associations between various human diseases and variant forms of ZIP8 have been reported. Four amino acid residues, V33, G38, S335, and I340, of human ZIP8 (hZIP8) are mutated in patients with congenital disorders of glycosylation (CDG), whose blood Mn levels are extremely low. […] We established DT40 cells respectively expressing the four mutant hZIP8s and compared the Mn- and Cd-transporting activity between the mutants and wild-type hZIP8.