BDNF and Parkinson disease: The expression of genes related to PD with high scores was extracted and found that SNCA, LRRK2, PINK1, TH, BDNF, and SOD2 were downregulated, while COMT, SNCAIP, CASP3, GFAP, and BCL2 were upregulated (Figures 3(a) and 3(b)).