MKI67 and amyotrophic lateral sclerosis: In contrast, assays of astrocyte proliferation and activation (Ki67, Figure 4D; GFAP expression level, Figure 4E), or levels of oxidative stress (Figure 4F), all showed no observed effect of treatment with any muscle EVs (neither MuV nor lmEV, neither ALS nor Healthy) compared to untreated astrocytes.