MAPT and frontotemporal dementia: They comprise following disorders: AD, a 3R/4R tauopathy, and frontotemporal lobar degeneration subtype tau (FTLD-tau) group, which includes: PSP, CBD, argyrophilic grain disease (AGD), all considered 4R tauopathies, and PiD, a 3R tauopathy (Kovacs, 2015; Arendt et al., 2016; Irwin, 2016; Kovacs, 2017).