In PASMCs under hypoxia or PDGF treatment, activated ERK/Akt pathway upregulates HIF-1α expression.368 In PASMCs from PAH patients and 5-HT-treated bovine PASMCs, the JNK pathway is activated, driving cell proliferation through Akt activation. The gene discussed is MAPK8; the disease is pulmonary arterial hypertension.