The Notch3/Hes5 signaling pathway plays a crucial role in the pathogenesis of PAH by regulating key cellular processes such as proliferation, apoptosis, and vascular remodeling (Bodas et al., 2022; Pokharel et al., 2023; Winicki et al., 2024). The gene discussed is HES5; the disease is pulmonary arterial hypertension.