Peripheral blood mononuclear cells (PBMCs) from patients with active tuberculosis were shown to have raised levels of Tregs in comparison to healthy controls (73).The ex vivo depletion of these CD25+ FoxP3+ cells from PBMCs of patients led to an increased expansion of antigen-specific IFN-γ+ T cells indicating that M. tuberculosis–induced Tregs were capable of suppressing these protective T cell responses. This evidence concerns the gene IFNG and tuberculosis.