NOS3 and pulmonary arterial hypertension: The observation that adult eNOS null mice that develop a range of cardiovascular diseases, including pulmonary arterial hypertension and cardiac dysfunction (Fagan et al., 2000; Li et al., 2004; Atochin and Huang, 2010), are relatively rare survivors that may carry some congenitally acquired malformations, strengthens the link between congenital and adult heart defects.