IGFBP6 and pulmonary arterial hypertension: Although direct evidence linking IGFBP-6 to PAH is limited, its established roles in regulating vascular smooth muscle cell behavior and inflammation, as observed in other cardiovascular diseases, indicate it may influence the pathogenesis of PAH through similar mechanisms (Wang et al., 2020; Venuto et al., 2023; Wang et al., 2022).