As shown in Fig. 3a, it is evident that apparent amounts of C4F6-reactive SOD1 were significantly higher in the ALS cases compared to those in the non-ALS cases including non-ND, PD, DLB, PSP, and AD (P = 2.5 × 10− 10, Mann-Whitney U-test) (Fig. 3a). Here, SOD1 is linked to Alzheimer disease.