CXCL8 and amyotrophic lateral sclerosis: A large number of studies reported elevated levels of inflammatory markers—cytokines, TNFα, IL-1β, IL-6, IL-8, TNF receptor 1, and vascular endothelial growth factor (VEGF)—in ALS serum and plasma; however, the inflammatory markers show no specificity for ALS diagnosis and progression ([116,117] and references therein).