Bronchial arteryenlargement is most frequently observed in CTEPH but is also observed inpatients with congenital heart disease182 and patients with IPAH and a BMPR-2 mutation.183 PVOD is rare and is characterized by mediastinal lymphadenopathy andinterlobular septal thickening,184,185 with or withoutassociated findings of alveolar edema, mediastinal lymphadenopathy in thesetting of a normal sized left atrium. The gene discussed is BMPR2; the disease is pulmonary venoocclusive disease.