IL21 and amyotrophic lateral sclerosis: A number of these have been reported as changed in ALS, including IL-1β, IL-1Rα, IL-1, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12p70, IL-13, IL-15, IL-17, IL-17A, IL-18 and IL-21.61,71 It has not been clearly demonstrated that the serum/plasma levels of these markers increase (or decrease) at baseline in ALS.64,65 However, some ILs found in CSF may have some utility in the separation of ALS from disease mimics.