In particular, it has been revealed that in the SOD1-G93A mice, the breakdown of blood–spinal cord barrier (BSCB) in the early ALS disease phase led to accumulation of blood-derived iron in the spinal cord, which initiates ALS by triggering early motor-neuron degeneration through iron-induced oxidant stress31. This evidence concerns the gene SOD1 and amyotrophic lateral sclerosis.