PLK2 and Parkinson disease: Interestingly, polo-like kinase 2 (PLK2) phosphorylates alpha-synuclein at S129, but rather than promoting pathology, this phosphorylation facilitates the clearance of alpha-synuclein through the lysosomal-autophagic degradation pathway, suggesting a potential neuroprotective role for PLK2 in PD (Alvarez et al. 2010; Chakraborty et al. 2017; Guo et al. 2019).