APP and Alzheimer disease: The association of largely amorphous amyloid structures with the occurrence of chemically-reduced iron deposits several hundred nanometers in diameter as observed here, was also reported in our X-ray spectromicroscopy examination of cortical tissue from APP/PS1 mice57, and isolated amyloid plaque material from AD subjects58; suggesting that Aβ/ferritin interaction may have acted as source for the formation of chemically-reduced iron in these instances.