GBA1 and Parkinson disease: The development of therapeutic agents that exploit the key pathological pathways in GBA-associated PD include the small molecular chaperone Ambroxol,33 which crosses the blood–brain barrier when administered orally, have been shown to increase GBA enzyme activity in primate models.34 Therefore, if such therapeutic strategies were to become available for humans, we would need to identify a window of opportunity before the onset of dementia in GBA-associated PD where such interventions would have the maximum impact.