APP and Alzheimer disease: Moreover, our recent synchrotron-based X-ray absorption studies have revealed the presence of nanoscale (ca. 200 nm) deposits of chemically-reduced iron within plaque structures located in the cortical tissue of APP/PS1 transgenic mice57, and amyloid plaque core material extracted from the grey matter in donated human brains from confirmed AD cases, including phases consistent with zero-oxidation-state iron in the latter58.