Characteristic accumulations of highly [[phosphorylated tau]] protein aggregates are found in several neurodegenerative tauopathies including [[Alzheimer’s disease]] (AD), [[progressive supranuclear palsy]] (PSP), [[corticobasal degeneration]] (CBD), and some forms of [[frontotemporal lobar dementia]] (FTLD-tau). It was assumed that these pathological [[tau]] aggregates are the toxic form of [[tau]].