SUMO1 and pulmonary arterial hypertension: Decreased miR-21 and lncRNA SOX2-OT prevent PASMC proliferation and pulmonary vascular remodeling, respectively, by the miR-21/WWP1/TGF-β1 signaling pathway and SOX2-OT/miR-455-3p/SUMO1 axis, and lncRNA SOX2-OT also serves as a novel biomarker for the diagnosis of PAH (110, 111).