No significant differences were noticed in the mean IFN-γ levels of those blood cultures stimulated with mycobacterial antigens from culture-positive (2.78±3.50 IU/ml) or culture-negative (4.24±3.86 IU/ml) TB patients or from patients with non-mycobacterial community acquired lung diseases (3.89±5.19 IU/ml) (Fig. 3C). The gene discussed is IFNG; the disease is tuberculosis.