There is a negative association between diabetes duration and insulin secretion.28 Also, reduced insulin receptor expression and downstream signaling in T lymphocytes have been shown in patients with diabetes.29 Because diminished insulin signaling includes reduced antigen-specific proliferation and proinflammatory cytokine production in T cells,30 decreased insulin production and altered insulin receptor–mediated signaling in T cells might contribute to increased TB risk in patients with diabetes of longer duration. This evidence concerns the gene INS and diabetes mellitus.