The level of EDI-positive species in the hSOD1WT medium was 0.079 ng/μg of medium protein, whereas that in the ALS-causing hSOD1 medium was over 0.11 ng/μg of medium protein (G93A, 0.123 ng; G37R, 0.129 ng; D90A, 0.110 ng; and G85R, 0.181 ng) (Figure 5a). Here, SOD1 is linked to amyotrophic lateral sclerosis.