STAT3 and pulmonary arterial hypertension: Previous studies have demonstrated various regulating functions of STAT3 signalling in PAH development.33, 34 STAT3 activation was found in both human and experimental models of PAH.35 Haemoodynamic forces which were induced by pressure overload, shear stress and cyclic strain were also upstream activators of STAT3.34 That may remind us the possible activation of STAT3 induced by the high haemodynamics in CHD‐PAH.