We demonstrate dysregulation of KLF2-induced miRNA signalling in endothelial cells and lung tissues from idiopathic PAH (IPAH) patients and heritable PAH patients with a KLF2 mutation and present evidence of homoeostatic and anti-remodelling effects of KLF2-induced miR-181a-5p and miR-324-5p in vitro and in vivo. This evidence concerns the gene KLF2 and idiopathic pulmonary arterial hypertension.