SOD1 and amyotrophic lateral sclerosis: It is, however, appropriate to mention that the downregulation of mutant SOD1 expression, through siRNA, restricted in skeletal muscle of SOD1 G93A mice did not improve muscle strength, and muscular selective knockdown of the mutant Sod1 transgene through Cre-Lox recombination did not affect disease progression of SOD1 G37R ALS mouse model [54].