CLIC4 expression in kidney of 4 week old mice. GFP staining in homozygous CLIC4-GFP knock-in (A-B) and WT mouse (C-D). Panels on the left show the entire organ, where CLIC4 expression is uniquely present in the renal cortex while absent in the medullary parenchyma. CLIC4 pattern of expression includes endothelial cells in arterioles (*) and glomerular tufts (G) (brown chromogen). Proximal tubule epithelia are intensely labeled while distal tubular epithelia are not labeled. Note glomerular visceral podocytes lack immunolabeling as well (arrows). Panel below is kidney from WT control mouse treated with anti-GFP, indicating lack of specific CLIC4-GFP expression. The signal apparent in (D) represents nonspecific sticking of antibody to the proximal tubule microvillus border. Hematoxylin counterstain. Bar = 50 um (B and D).