The enhanced plasma level of proinflammatory cytokines (IL-1β, IL-2, IL-4, IL-6, IL-7, IL-12, IL-16, IL-17, IL-18, TNF-α, GM-CSF, IFN-γ, etc.)and chemokines (CXCL-8, CXCL-10, CCL-1, CCL-2, CCL-3, CCL-4, CCL-5, etc.)remains as a diagnostic feature in RA patients [41]. Here, IL17A is linked to rheumatoid arthritis.