IL6 and familial Mediterranean fever: Although there are no specific serum biomarkers for the diagnosis of FMF, previous reports have shown that serum interleukin (IL)-1β, soluble IL-2 receptor, IL-6, tumor necrosis factor-α (TNF-α), IL-10, IL-12, IL-17A, and IL-18 are important for the pathogenesis of FMF [6–12].