Hepatic iron staining. Perl Prussian blue stain of liver sections from a tumor-free mouse (A) and a hepcidin-secreting tumor mouse (B) on a high-iron diet. Unlike in tumor-free mice where spindle-shaped Kupffer cells (arrows) are the most prominent blue-staining cells, in mice with hepcidin-secreting tumors there is diffuse blue staining of the hepatocytes, showing that the increased hepatic iron is within hepatocytes. Scale bars represent 50 μm.