SLC39A5 and osteosarcoma: We used the human osteosarcoma cells, U2OS, for the transient transfection of ZIPs (specifically, ZIP4, ZIP5, ZIP7, and ZIP13) and the Madin–Darby canine kidney (MDCK) cells harboring the FLp-InTM T-Rex for the stable transfection of ZIPs (specifically, ZIP4, ZIP5, and ZIP7).