CXCL8 and rheumatoid arthritis: A variety of cytokines released by different T cell subsets are involved in the inflammatory microenvironment of RA (21).For example, Th17 cells can promote macrophages, synoviocytes and other cells to secrete a large number of inflammatory factors such as IL-1β and IL-6 by producing IL-17 and also contribute to the production of CXCL1, CXCL2, CXCL8 and other chemokines (4, 22).