TH and Parkinson disease: Notably, two proteasome-directed intrabodies, VH14*PEST (targeting α-Syn non-amyloid component region) and NbSyn87*PEST (directed against α-Syn C-terminal region), injected into SN of overexpression-based PD rodent models, markedly reduced the level of phosphorylated pS129 α-Syn, increased TH immunoreactivity, dopamine transporter density, and improved motor functions [57].