SNCA and Parkinson disease: Neuroinflammation with resulting alpha-synuclein accumulation is a hallmark event in PD, and is closely associated with impaired blood-brain-barrier (BBB) permeability and microvascular dysfunction (Zhang et al., 2005; Sarkar et al., 2014; Sweeney et al., 2018), in particular given that certain BBB-targeting metalloproteinases (MMP) can be activated by inflammatory cytokines and chemokines (Germano et al., 2000; Jin et al., 2012).