PCSK1N and Alzheimer disease: Immunofluorescence studies have similarly shown that proSAAS co-localizes with aggregated proteins involved in neurodegenerative disease, namely tau tangles in dementia (Kikuchi et al., 2003); Abeta plaques in AD (Hoshino et al., 2014); and Lewy bodies in PD (Helwig et al., 2013).