CXCL8 and amyotrophic lateral sclerosis: A recent meta-analysis (128) combining serum and plasma measurements from 25 studies found TNF-α, TNF-receptor 1, IL-6, IL-1β, IL-8, and VEGF were significantly elevated in ALS, but of note is that results for IL-1β, IL-6, and VEGF may have been skewed by one study.