NOS2 and pulmonary emphysema: A series of selective inhibitors of iNOS have been developed and in a study, one of these, the pro-drug of L-N6-(1-imminoethyl)lysine gave a lasting reduction in NO concentrations in exhaled breath [126], suggesting that the inhibition of peroxynitrite generation by antioxidants or iNOS inhibitors offers a therapeutic approach in emphysema and may restore corticosteroid responsiveness.