In a study of PAH rats and COPD patients, it is found that inhibition of pyruvate dehydrogenase kinase (PDK), which is highly expressed in right ventricular fibroblasts, can accelerate degradation of HIF-1α, inhibit right ventricular fibrosis and hypertrophy, and improve right ventricular functions61. Here, HIF1A is linked to chronic obstructive pulmonary disease.