Active TB patients with DM display higher levels of circulating type-1 (Th1) cytokines such as IFN-γ and tumor necrosis factor (TNF) in comparison to TB patients without DM (41), while LTBI in the presence of DM or pre-DM were associated with reduced levels of these important mediators which are involved in the control of Mtb (42). This evidence concerns the gene IFNG and diabetes mellitus.