TLR2 and diabetes mellitus: DM susceptibility to TB infection is highly dependent on the ability of the DM individual’s immune response to eradicate TB, where the conditions of hyperglycemia and cellular insulinopenia contribute directly to impaired innate immune cell function, such as the decreased phagocytosis of macrophages, the impaired secretion of interleukin-12 (IL-12), the function of Toll-like receptor-2 (TLR-2), and the decreased expression of the molecule major histocompatibility complex class-II (MHC-II) [7], which causes DM sufferers to become easily infected with TB [8].