Indeed, we recently observed that M. tuberculosis-specific CD4 T-cell cytokine profile of PTB patients from Tanzania were primarily composed of polyfunctional Th1 and Th2 cells, while M. tuberculosis-specific CD4 T-cell cytokine profiles of TB patients from South Africa were dominated by single IFN-γ and dual IFN-γ/TNF-α (25). Here, IFNG is linked to tuberculosis.