NOS2 and pulmonary emphysema: Our own previous studies investigating nitric oxide (NO) as well as sGC-cGMP signaling revealed that 1) an inhibition of the NO-producing enzyme inducible NO synthase (iNOS) [9] and 2) a stimulation of the soluble guanylate cyclase (sGC) [15] prevented cigarette smoke-induced emphysema and PH.