Among older patients with TB, an age-associated over-representation of regulatory T cells, along with a significant reduction in the IFN-γ/IL-4 ratio, has also been reported, along with a significant reduction in other pro-inflammatory effector T-cell cytokines, such as IL-17A, IL-2, TNF-α, and polyfunctional (IFN-γ+ TNF-α+) T cells. The gene discussed is IFNG; the disease is tuberculosis.