The therapeutic potential of both cathepsins was tested in different human and murine models exhibiting SNCA pathology: In human cell models (H4 cells and DA-iPSn), the reduction of pathology-associated SNCA was evaluated via sequential extraction protocol and IF utilizing various SNCA antibodies, as well as an ELISA specific for aggregated SNCA in PD-DA-iPSn. This evidence concerns the gene CTSS and Parkinson disease.