MMP9 and Parkinson disease: (1) α-synTotal decreased significantly in PD, compared to CTR (p = 0.004); (2) α-synOligo increased significantly in PD compared to CTR (p = 0.001); (3) the level of changes in analyzed parameters was associated with sex; (4) total protein, CCL2, DJ-1, and MMP9 were increased in PD but changes were not statistically significant.