HMGB1 and pulmonary arterial hypertension: In this study, we explored the relationship between HMGB1 and pulmonary hypertension, investigating whether HMGB1 inhibition by glycyrrhizin attenuates disease progression of pulmonary hypertension and in turn translates into mortality benefit, by using a well-established experimental pulmonary hypertension model induced by monocrotaline sodium (MCT).