Three of these latter patients had definite HHT and hemodynamics that were consistent with PAH (mPAP 49 mmHg and PVR 4.1 WU, mPAP 32 mmHg and PVR 3.6 WU, and mPAP 36 mmHg and PVR 3.7 WU) but had factors such as COPD or high positive ANA that confounded the diagnosis of PAH related to HHT and thus were excluded; these patients were lost to follow-up. The gene discussed is BTG3; the disease is pulmonary arterial hypertension.