AKT1 and pulmonary arterial hypertension: IGFBP-2 contributes to PAH by stimulating PASMC proliferation via integrin/PI3K/Akt pathway and other non–IGF pathways, regulating PTEN, and linking vascular inflammation to remodeling; its elevated circulating and tissue levels correlate with disease severity and prognosis. and Its elevated circulating/tissue levels correlate with disease severity and prognosis, supporting its potential as a prognostic biomarker and therapeutic target.