Investigations in the MPTP-induced PD mouse model further showed that in the MPTP plus lipopolysaccharide (LPS)-treated mice, the hyperphosphorylated Tau (p-Tau) protein levels in the brain homogenates significantly increased in the vehicle-treated group, whereas strikingly, 2 h after a single IV injection of plasminogen, both the monomeric and low molecular weight (LMW) p-Tau levels in the plasminogen-treated group were significantly lower than those in the vehicle-treated group (Fig. 2A–B). This evidence concerns the gene MAPT and Parkinson disease.