PVR and Parkinson disease: Strikingly, the WβC‐pathway plays a critical role during development, in adult and aging SVZ‐, Aq‐PVR‐ and SGZ‐niches, thus providing a robust homeostatic regulatory mechanism for NSC survival, proliferation, differentiation and integration, and bearing the potential to respond to injury and regeneration with potential consequences for both non‐motor‐ and motor‐related features of PD.