NEDD4 and alpha synuclein measurement: In this context, Nedd4, a ubiquitin ligase that targets proteins to lysosomes, provides an enzymatic link between this striking association of α-synucleinopathy and lysosomal degradation, and given its specificity for only a few protein-substrates, an opportunity for a targeted therapy aimed at preventing the accumulation of α-synuclein in brain.