Consistent with this observation, immunostaining and western blotting in the striatum also showed remarkable decreases in the TH-positive fibers (6-OHDA vs control: p = 0.0003) and TH protein levels (6-OHDA vs control: p < 0.0001) on the injected side of striatum of PD mouse brains compared with control mouse brains that were restored after OCN treatment (6-OHDA vs 6-OHDA+ 4 μg/kg OCN: TH-positive fibers, p = 0.0471; TH protein levels, p = 0.0477) (Fig. 1d). The gene discussed is TH; the disease is Parkinson disease.