IFNG and brucellosis: The level of Arginase-1, IL-10, TGF-β1 and IL-6 was significantly higher in chronic brucellosis group than that in healthy control group (P<0.01; Figures 2A-D), while the level of IFN-γ, TNF-α and IL-2 varied insignificantly between two groups (P>0.05; Figures 2E-G), suggesting that the higher immunosuppression cytokines in chronic brucellosis patients than that in heathy individuals.