Emerging evidence suggests that IGFBP-3 may also interact with other signaling molecules implicated in vascular remodeling, such as transforming growth factor-beta (TGF-β) and vascular endothelial growth factor (VEGF), both of which play pivotal roles in PAH (Hudson et al., 2014). Here, TGFB1 is linked to pulmonary arterial hypertension.