Within 232 individuals, the disparities in absolute quantitative IFN-γ levels between the QFT-GIT TB antigen tube and the QFT-Plus TB1 and TB2 antigen tubes spanned a spectrum of −7.26 IU/ml to 9.83 IU/ml, −0.26 IU/ml to > 10 IU/ml and −0.23 IU/ml to > 10 IU/ml, respectively. The gene discussed is IFNG; the disease is tuberculosis.