TXN and pulmonary hypertension: At present, TXNRD1 has not yet been reported in pulmonary hypertension, while the substrate of TXNRD1, thioredoxin1 (Trx1), was claimed to be increased in hypoxia-induced PASMC proliferation (31), whereas Zimmer et al. observed that MCT-induced PAH animal model promoted a reduction in Trx1 (32).