Dysfunctional NO-sGC-cGMP signaling may contribute to pulmonary vascular disease. sGC ‘modulators’ directly stimulate heme-containing and heme-free sGC. The beneficial effects of sGC ‘modulators’ extend beyond vasodilation. Attenuation of fibrosis has been seen in rat models. sGC modulators stimulate the NO-sGC-cGMP signaling pathway.