In the open field test, compared with the CTRL group, the number of squares of crossed was decreased in PD rats, whereas EGCG increased the number of squares of crossed; moreover, EGCG did not decrease the number of squares of crossed in PD rats when CID755673 was used to inhibit the PKD1 expression, and Ad-PARP-1 was used to activate the Parthanatos (Figure 2a). Here, PKD1 is linked to Parkinson disease.