CXCL8 and rheumatoid arthritis: Thus, pathogenesis of RA has been closely related to various inflammatory proteins, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6), while several interleukins, including interleukin-1 (IL-1), IL-6, interleukin-8 (IL-8), interleukin12 (IL-12), and interleukin-32 (IL-32), have been proposed as promising biomarkers of a series of rheumatic ADs [20,21,22,23,24].