TNF and amyotrophic lateral sclerosis: Levels of proinflammatory cytokines, including interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α), are elevated in the plasma and cerebrospinal fluid (CSF) of people with ALS, reinforcing the role that systemic inflammation may play in the disease mechanism and progression (Tortelli et al., 2020).