IFNG and tuberculosis: The following cytokine ratios were found to be different between non-TB diseases and extrapulmonary TB: PPD induced TNF-α/IL-2 (p<0.001), IFN-γ/IL-2 (p = 0.001) and ESAT-6 induced TNF-α/IFN-γ (p = 0.026), TNF-α/IL-2 (p = 0.008), and IFN-γ/IL-2 (p<0.001).