1995; Chen et al. 1997). Increased ET‐1 levels are observed in other animal models of PH, including the Fawn‐Hooded rat (Stelzner et al. 1992), monocrotaline‐treated animals (Frasch et al. 1999), and the SU5416‐hypoxia rat (Rafikova et al. 2013), as well as in patients with PH of varied etiologies, including pulmonary arterial hypertension (Giaid et al. 1993), chronic thromboembolic PH (Bauer et al. 2002), congenital heart disease (Ishikawa et al. 1995), and persistent pulmonary hypertension of the newborn (Rosenberg et al. 1993). The gene discussed is EDN1; the disease is pulmonary arterial hypertension.