SOD1 and neurodegenerative disease: Although our results were obtained under non-physiological conditions, such as Cu2+ binding in the absence of CCS (required for proper Cu2+ binding to the catalytic site of SOD1) [14], nevertheless, our findings are intriguing and will yield mechanistic insight into how free radical-mediated SOD1 mutants aggregate under pathological conditions observed in a number of neurodegenerative diseases.