Serum TNF-α (a), IFN-γ (b), IL-10 (c), and IL-17 (d) cytokine levels determined using ELISA in healthy volunteers, patients with T2DM without evidence of infection or previous exposure to TB, and TB-T2DM patients at the baseline of the DOTS scheme. The data represent means and standard deviations of the results, and the asterisks indicate significance as follows: *, P < 0.05; ***, P < 0.0001 (for comparisons between groups by ANOVA and post hoc tests).