IL6 and rheumatoid arthritis: Inflammatory markers such as IL-6, IL-10, the neutrophil-to-lymphocyte ratio (NLR), the platelet-to-lymphocyte ratio (PLR), TNF-α, and C-reactive protein (CRP) play important roles in the pathogenesis of RA and are highly expressed in serum and synovium fluid of RA patients [22,23].