SOD1 and amyotrophic lateral sclerosis: SOD1-G93A Tg mice exhibit no changes in EAAT2 levels at 14 weeks old [80]; however, decreased immunoreactivity of EAAT2 was found in the ventral horn of the lumbar spinal cord in 14- to 18-week-old mice, which suggests downregulation prior to symptoms in SOD1 ALS.