Nil-tube IFN-γ levels were significantly higher in the active TB group (median = 0.18 IU/mL; interquartile range: 0.09–0.45 IU/mL) than in the IGRA-positive non-TB (0.11 IU/mL; 0.06–0.23 IU/mL) and IGRA-negative non-TB (0.09 IU/mL; 0.05–0.15 IU/mL) groups (P < 0.0001). The gene discussed is IFNG; the disease is tuberculosis.