There is a growing body of preclinical evidence from cell and animal models of PD (6-hydroxydopamine-injected rats, transgenic mouse models and transgenic fly models) showing that ambroxol has neuroprotective effects through upregulation of glucocerebrosidase (GCase), which leads to reduction of α-synuclein pathology, and improvement of mitochondrial function [17]. Here, GBA1 is linked to Parkinson disease.