CXCL8 and amyotrophic lateral sclerosis: Of the activated inflammatory markers in our study, IL-6, IL-8, TNF-α, IL-10, IL-4, and IL-13 can be produced physiologically by contracting muscle fibers and can be overexpressed during strength training.27 It is possible that hyperexcitable muscles prone to fasciculation and atrophy in ALS may also cause overexpression of these markers.