One study of mouse models revealed that transplantation of the precursors of mutant SOD1 astrocytes into the spinal cords can lead to degeneration of motor neurons [88], whereas transplantation of wild type astrocytic precursors into ALS mouse models results in the decrease of motor neurons death, which indicates that ALS astrocytes have harmful or toxic effects on motor neurons in vivo [89]. This evidence concerns the gene SOD1 and amyotrophic lateral sclerosis.