To test whether inhibition of USP30 catalytic activity can recapitulate the protective effects on the nigrostriatal system observed in Usp30 KO mice, we tested the USP30i MTX115325 (WO 2021/249909 A1) in a closely related version of the AAV-A53T-SNCA PD mouse model as we described for the Usp30 KO studies. Here, USP30 is linked to Parkinson disease.