TNF and amyotrophic lateral sclerosis: The evidence that astrocytes actively modulate the inflammatory response and the increased serum/plasma and cerebrospinal fluid (CSF) levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), and interferon-β (INF-β) [73] encouraged the study of astrocytes as inflammatory mediators in ALS.