GBA1 and Parkinson disease: Variants in the glucosylceramidase beta 1 (GBA1) gene, which encodes the lysosomal enzyme glucocerebrosidase (GCase) and is associated with Gaucher disease (GD), a lysosomal storage disorder involving immune system dysfunction [27], have also been identified in PD patients, suggesting a potential link between lysosomal dysfunction, immune dysregulation, and PD pathogenesis [28].