CD4 and pulmonary tuberculosis: Moreover, the increased IFN-γ production from PBMCs of pulmonary TB patients upon stimulation with either early secretory antigenic target of 6 kDa (ESAT6) or culture filtrated protein 10 (CFP10), and the high expression of IFN-γ by CD4+ T cells and CD8+ T cells have been recently demonstrated [39].