Along these same lines, studies employing experimental in vitro and in vivo models of Salmonella infection have demonstrated that a major mechanism used by macrophages to restrict infection is to enhance the expression of ferroportin, therefore decreasing the intracellular iron pool, which also enhances the levels of iNOS expression and NO production in response to the reduction of intracellular iron concentration [170,171,172]. The gene discussed is NOS2; the disease is infection.