CD8A and amyotrophic lateral sclerosis: Notably, the compositional and functional status of T cells in blood and cerebrospinal fluid (CSF) in ALS patients was recently associated with both disease progression rates and survival21: Increased CD8+ T‐cell counts in the peripheral blood have already been linked to rapid disease progression,5, 22 while neuroprotective effects have been postulated for regulatory T cells and natural killer (NK) cells.22, 23, 24