MAPT and Alzheimer disease: We tested whether ferritin is able to suppress the rough-eye phenotypes of flies that express: (1) the dementia-linked variant of tau (tau R406W) (Wittmann et al., 2001); (2) an expanded polyglutamine polypeptide (Q48), as a model of HD; and (3) TAR DNA-binding protein 43 (TDP43), which is implicated in neurodegenerative disorders including AD and motor neurone disease (Gendron et al., 2013).