Newly-developed diagnostic tools such as whole blood interferon gamma (IFN-γ) release assays (IGRAs) and real time polymerase chain reaction (PCR)-based GenXpert [4,6-8] are unsuitable for routine clinical use in resource poor settings, where the majority of TB cases occur, as many of these techniques require sophisticated laboratory set-ups, equipment and trained personnel. The gene discussed is IFNG; the disease is tuberculosis.