HSP90AA1 and Alzheimer disease: Augmented levels of α-synuclein or α-synuclein-containing aggregates are also characteristic of other neurodegenerative diseases including Lewy body dementia, multiple system atrophy and AD (Halliday et al., 2011; Serrano-Pozo et al., 2011; Ingelsson, 2016), forming a group of diseases termed “synucleinopathies.” The involvement of molecular chaperones in PD was first suggested by the observation that Hsp90, Hsp70, Hsp60, Hsp40, and Hsp27 were localized in Lewy bodies (McLean et al., 2002; Uryu et al., 2006; Leverenz et al., 2007).