The precise mechanisms underlying the disease-modifying effects of apelin receptor ligands are not fully understood, but anti-apoptotic and anti-proliferative actions have been observed in PAECs and PASMCs (Yang et al., 2019; Read et al., 2021), promoting vascular homeostasis that is perturbed in PAH (Alastalo et al., 2011; Frump et al., 2021). This evidence concerns the gene APLNR and pulmonary arterial hypertension.