Though GFAP upregulation is usually associated with astrocyte proliferation and reactive astrogliosis [59], no increased expression was noticed in any of the samples; however, a significant downregulation was found in two of the mSOD1-ALS patients, one female and one male (ALS2 and ALS3, p < 0.01 and p < 0.05, respectively, Figure 2A). Here, GFAP is linked to amyotrophic lateral sclerosis.