SOD1 and amyotrophic lateral sclerosis: Furthermore, data obtained from G93A-SOD1 transgenic mice, the most common animal model for ALS, showed the activation of caspase-1 and IL-1β in the microglia by ALS-linked mutant SOD1 and demonstrated that caspase-1 or IL-1β gene knockout or the use of recombinant IL-1Ra resulted in a reduction of inflammation.