PD patients showed an increased level of VEGF, PIGF, and VEGFR2 in the CSF that correlated with more permeable BBB (increased CSF/plasma albumin ratio) and increased neuroinflammation as determined with monocyte chemotactic protein-1 (a marker for glial activation) immunostaining (Shorena Janelidze et al. 2015). This evidence concerns the gene VEGFA and Parkinson disease.