IFNG and tuberculosis: Using ESAT-6 and CFP-10, two specific antigens encoded in the RD1 locus of the bacterial genome, which distinguish M. tuberculosis from other Mycobacteria, has increased specificity and sensitivity of IFN-γ ELISPOT assay.[14] This study reports the results of the first evaluation of ex vivo INF-γ based assay (TSPOTTB) for the diagnosis of TB in adults by recombinant antigens of native M. tuberculosis C as the standard strain of Iran.