TGFB1 and pulmonary arterial hypertension: Vascular remodeling is a hallmark feature in PAH and is characterized by excessive cell proliferation, abnormal release of inflammatory cytokines such as interleukin 1 (IL-1), IL-6, and tumor necrosis factor alpha (TNFα), and the upregulation of growth factors such as TGFβ (António et al., 2022).