CXCL8 and fibromyalgia: The levels of IL-1, IL-6, IL-8, and TNF-α were found to also be increased in the blood of patients with fibromyalgia [8,9,10]: an association between IL-8, IL-6 and the severity of the disease has been demonstrated, thus showing that the release of pro-inflammatory cytokines negatively links to fibromyalgia and its prognosis [11].