TNF and rheumatoid arthritis: The role of IL-17 is highly valued in RA because it can induce a variety of cells (synovial cells, macrophages, etc.)to produce a large number of inflammatory factors (IL-1β, IL-6, TNFα), and it plays an important role in the production of chemokines (CXCL1, CXCL2, CXCL8, CCL2, CCL7) [30].