Third, silenced JAG2 gene (i.e. endMT promoter) and GATA3 gene (i.e. endMT transcriptional regulator) remarkably suppressed the expression of endMT biomarkers, suggesting that the JAG2‐GATA3 signalling was essential for the endMT initiation and propagation of endMT and PAH. Here, GATA3 is linked to pulmonary arterial hypertension.