High IFN-γ Nil levels in the 'non-TB' group, were only found in the two HIV positive patients (4.2 and 8.8 IU/1 × 106 PFMCs) and not in the HIV negative malignancy patients (0.14–0.65 IU/1 × 106 PFMCs). The gene discussed is IFNG; the disease is cancer.