In patients with definite TB who had a CXR compatible with active disease, median IFN-γ responses did not differ significantly between those who had cavities (52/124) and those who did not (72/124) when measured using TSPOT.TB [140 (80–208) vs. 112 (33–190) SFC⋅10−6 PBMCs; p = 0.12], QFT-GIT [3.0 (1.0–5.8) vs. 1.6 (0.4–4.6) IU⋅ml−1; p>0.05] or PPD ELISPOT [106 (28–194) vs. 117 (34–159) SFC⋅10−6 PBMCs; p = 0.88]. The gene discussed is IFNG; the disease is tuberculosis.