Tg⁺ mice have stainable iron in the bone marrow. (A-B) Prussian blue stain detected iron in the bone marrow of 2 Tg⁻ mice. (C-D) Prussian blue stain detected iron in the bone marrow of 2 Tg⁺ mice. Run-to-run variation accounts for differences in the intensity of nuclear fast red counter stain.