Immunohistochemical localization of HSD3B4 in human and mouse control and diabetic kidneys. Podocytes and tubular epithelial cells stain positive (brown) with rabbit anti-HSD3B4 antibody in control human kidney tissue (A) and in kidneys with advanced diabetic nephropathy (B). Nuclei were counterstained with hematoxylin. HSD3B4 colocalized with podocyte marker synaptopodin in mice (C–E). Frozen control (4-week-old 129 SvJ) mouse kidney sections were stained with anti-HSD3B4 (red) (C) and anti-synaptopodin (green) (D) and their overlap (E). The arrows show positive HSD3B4 staining in podocytes.