MAPT and Alzheimer disease: Aberrant phosphorylation of tau has been broadly implicated in neurodegenerative diseases known as tauopathies, including AD, frontotemporal dementia, progressive suprenuclear palsy, etc., and activation of the PAR-1/MARK-tau pathway has been observed in AD subjects and animal models (Chin et al., 2000; Wang et al., 2007; Iijima-Ando et al., 2009; Zempel et al., 2010; Yu et al., 2012).