When the tau protein has malfunctioned, it causes a wide range of problems such as progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), traumatic brain injury (TBI), and frontotemporal dementia (FTD) (Graff-Radford and Woodruff, 2007; Mietelska-Porowska et al., 2014). Here, MAPT is linked to frontotemporal dementia.