No differences were seen between TB cases and TST+ contacts for any cytokine but TB cases had the highest level of all cytokines compared to TST+ and TST− HHC with IFN-γ being produced at the greatest amount (median[interquartile range (IQR)] = 2923[1101–5819]pg/mL for TB cases, 2043[316–7573]pg/mL for TST+ contacts but only 201[46–496]pg/mL for TST− contacts (Fig. 1A). Here, IFNG is linked to tuberculosis.