FGF21 and hyperuricemia: In the present study, we aimed to: 1) characterize and compare the inflammatory proteomic signatures of gout and asymptomatic hyperuricemia, 2) functionally characterize the identified fibroblast growth factor 21 (FGF-21) biomarker in relation to cytokine production, and 3) monitor alterations in the proteomic profile of patients with gout following urate-lowering therapy.