SOD1 and amyotrophic lateral sclerosis: These ALS-causing hSOD1 mutants are categorized into the following five groups on the basis of the mutational sites related to hSOD1 stability [21]: (i) wild-type-like mutants (e.g., G93A, G37R, and D90A), (ii) metal-binding site mutants (e.g., G85R), (iii) disulfide forming cysteines mutants (e.g., C146R), (iv) dimer interface mutants (e.g., A4V), and (v) C-terminally truncated mutants (e.g., G127X).