However, a study testing the plasma of ALS patients showed abnormal levels of cytokines such as interleukin (IL)-1β, interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-8 (IL-8), interleukin-10 (IL-10), interleukin-12p70 (IL-12p70), interleukin-13 (IL-13), tumor necrosis factor-α (TNF-α), interferon-γ (INF-γ), creatine kinase (CK) and ferritin compared to the control group [44]. Here, CXCL8 is linked to amyotrophic lateral sclerosis.