BMPR2 and idiopathic pulmonary arterial hypertension: Although at least nine genes are associated with childhood-onset PAH nowadays, BMPR2 has been identified by a body of evidence as the major risk PAH gene, and approximately 50%–80% of HPAH and 10%–40% of IPAH are thought to be driven by BMPR2 mutations; thus, restoring BMPR2 expression to cure PAH seems to be the most reasonable and important approach of genetic therapy (Zhu et al., 2018a; Rosenzweig et al., 2019; Zhu et al., 2019; Ivy and Frank, 2021; Rai et al., 2021; Cruz-Utrilla et al., 2022).