Note, however, that in hBMVECs, only a small fraction of total ZIP8 is in the plasma membrane compared to total cellular protein, a finding reported also in the A549 lung epithelial and HIBCPP choroid plexus papilloma cell lines (41, 42), and human proximal tubular epithelial cells (43). Here, SLC39A8 is linked to choroid plexus papilloma.