OTUB1 and pulmonary arterial hypertension: In pulmonary artery smooth muscle cells and a pulmonary arterial hypertension rat model, hypoxia (3% O2 for cells and 10% O2 for mice, respectively) induces the deubiquitinase OTU domain-containing ubiquitin aldehyde-binding protein 1 (OTUB1), to stabilize SLC7A11, and eventually inhibiting erastin-induced ferroptosis [115].