RAB8A and Parkinson disease: The lack of an increase in phospho-Rab8 phosphorylation rate in PD uEVs is intriguing as phosphorylation of Rabs has been assessed in other sample types such as patient derived neutrophils, where an increase in Rab10 phosphorylation rate was observed in patients carrying the LRRK2 G2019S or VPS35 D620N mutations compared to healthy controls25.