Interestingly, breeding SOD1G93A mice with recombinant-activating gene 2 (RAG2−/−) knock-out mice, which lack functional T-and B-lymphocytes, did not affect disease onset, but decreased the life-span and disease duration of the ALS mice, suggesting that T or B lymphocytes contribute to protection [27]. This evidence concerns the gene RAG2 and amyotrophic lateral sclerosis.