Kim et al. demonstrated that the activity of MEF2 (MEF2A and MEF2C) is remarkably impaired in pulmonary arterial endothelial cells derived from the subjects with pulmonary arterial hypertension (PAH), and the restoration of the impaired function of endothelial MEF2 rescues PAH [18]. Here, MEF2A is linked to pulmonary arterial hypertension.