TNF and diabetes mellitus: DN is closely associated with the chronic low-grade inflammation and activation of the innate immune system[2-4]; and this is observed in patients with diabetes in the elevated serum levels of antibodies[5,6] and several inflammatory cytokines, primarily interleukin (IL)-1, IL-6, and IL-18, as well as C-reactive protein and tumor necrosis factor (TNF)-α[2,3,5].