There were higher mean (4.25 IU/ml) and median (3.86 IU/ml) TB2 tube IFN-γ responses compared to that of the TB1 IFN-γ tube responses (mean 3.95IU/ml, median 3.15IU/ml), p<0.001 among those with a HHC for previous TB treatment. The gene discussed is IFNG; the disease is tuberculosis.