Notably, moderate decrease (approx. 40% reduction) in the viability was observed in the PDSOD1 and PSPSOD1 cases (P < 0.01 in PDSOD1/PSPSOD1 vs. non-ND and also vs. ALS) but not in the PD cases without the misfolded SOD1 (P > 0.05 in PD/DLB vs. non-ND) (Fig. 9a, white bars). Here, SOD1 is linked to Parkinson disease.