In summary, the results of this study demonstrate that in PTB patients serum cytokine including TNF-α, IL-4, sIL-2R and IFN-γ level might not serve as a useful biomarker for predicting bacillar burden, while serum TNF-α and IFN-γ levels both may be useful tools for monitoring anti-TB chemotherapeutic treatment response. The gene discussed is IFNG; the disease is tuberculosis.