Alternatively, apparent amounts of C4F6-reactive SOD1 in CSF of ALS were significantly decreased by pre-incubation of the CSF samples with either 100 μM CuSO4 or 100 μM ZnSO4 (Fig. 8b), implying the metal-deficiency of SOD1 in CSF of ALS cases. This evidence concerns the gene SOD1 and amyotrophic lateral sclerosis.