The present invention is directed, in part, to the treatment of a subject having a neurodegenerative disorder, such as Parkinsons disease (PD), by providing glucocerebrosidase enzyme. The enzyme may be provided, e.g., through gene therapy or by administration of a glucocerebrosidase protein. Accordingly, the present invention encompasses glucocerebrosidase nucleic acids or proteins for use in the treatment of PD or other neurodegenerative disorders.