S100A4 and amyotrophic lateral sclerosis: Remarkably, S100A4 over-expression in glial cells was detectable at the pre-symptomatic phase of the disease in SOD1-G93A animals [34], data in accordance with the S100A4 gene up-regulation previously shown in the astrocytes of pre-symptomatic SOD1-G37R ALS mice [64], implying that S100A4 could represent a candidate molecule involved in the early ALS pathogenic mechanisms.