APP and Alzheimer disease: It has been reported that it closely correlates with amyloid pathology (van Duijn et al., 2017), infiltrates Aβ-containing plaques (Kenkhuis et al., 2021) and contributes to amyloidosis (Bush, 2003) while iron+ cells cluster around Aβ plaques in tissue from AD patients (Meadowcroft et al., 2015), as they do in tissue from APP/PS1 mice (McIntosh et al., 2019).