IL17A and Parkinson disease: MPTP injection induced a noticeable boost in serum levels of TNF-α, IL-1β, IL-6, IL-17, GM-CSF, and IFN-γ: 2.33-fold, 4.53-fold, 4.57-fold, 12.28-fold, 5.56-fold, and 1.90-fold in PD mice, respectively (Fig. 4, P < 0.01 versus control); these levels were completely reversed by VSL#3 and hMSCs alone and in combination (P < 0.05 versus PD).