Organic nitrate therapy induces neurohormonal (counter-regulatory) activation of vasoconstrictor pathways including the RAAS as a consequence of GTN-induced hypotension, but this response may be also redox-driven as a consequence of increased endothelin-1 or angiotensin-II expression/release and signaling (Munzel et al, 2013; Munzel et al, 2011). The gene discussed is EDN1; the disease is gestational trophoblastic neoplasm.