TNF and tuberculosis: Details from a systematic review of the Mtb-specific cytokine biomarkers revealed few of the significant combinations of cytokines IL-2 and IFN-γ, IL10 and IFN-γ, IFN-γ and IP-10, IFN-γ and TNF-α, and IL-2 and TNF-α which shows potential in discriminating between active TB and LTBI (108).