STAT3 and rheumatoid arthritis: In rheumatoid arthritis (RA), cytokine-mediated inflammation, predominantly IL-6, IL-1 and TNF-α, engages the gp130–STAT3 pathway, shifting hepatocyte protein synthesis toward positive acute-phase proteins and down-regulating albumin (35–37); capillary leak, hemodilution, and catabolic effects further lower circulating levels.