Also, in synucleinopathies such as certain forms of Parkinson’s disease (PD) or, for instance, in SOD1- or TDP-43-linked ALS, disease protein cleavage was identified as a disease-modifying factor (Wright and Vissel, 2016; Bluhm et al., 2021; Chhangani et al., 2021). Here, SOD1 is linked to Parkinson disease.