The aggregation of misfolded proteins is recognized to be the common pathological feature of neurodegenerative diseases, such as Aβ and hyperphosphorylated Tau in AD, mutant α-synuclein in PD, and mHtt in HD, as well as SOD1 and TDP-43 in ALS [5, 34, 35] (Figure 1). The gene discussed is MAPT; the disease is Parkinson disease.