LRRK2 and Parkinson disease: Two other studies, sponsored by the Michael J. Fox Foundation for Parkinson’s Research (NCT03775447, Fox BioNet Project Extracellular Vesicles ECV-003; and NCT04603326, Fox BioNet Project ECV-004), are focused on optimizing the isolation of EVs from human cerebrospinal fluid (CSF) to detect levels and activity of LRRK2, a protein associated with PD.