PSG5 and idiopathic pulmonary arterial hypertension: The mRNA levels of octamer-binding transcription factor 4 (Oct 4) pseudogene Oct-4-psG1 and Oct-4-psG5 are significantly down-regulated in pulmonary arterial smooth muscle cells (PASMC) in patients with idiopathic pulmonary arterial hypertension (IPAH), indicating that Oct-4-psG1 and Oct-4-psG5 are involved in IPAH [51].