The findings that SOD1 mutant proteins with biophysical properties similar to wild type SOD1 (wtSOD1); including D90A29 and L117V30, cause ALS, as well that overexpression of wtSOD1 causes an ALS-like disease in transgenic mice24, supports an emerging hypothesis that wtSOD1 contributes to ALS. The gene discussed is SOD1; the disease is amyotrophic lateral sclerosis.