Vascular remodeling in the lung is further facilitated by HIF1 via transcriptional repression of miRNA-223 in PASMCs leading to increased PARP-1 expression (166), via a feedback loop with KLF5 (see above, 86) and by HIF1-dependent upregulation of plasminogen activator inhibitor-1 (PAI-1) (167) and Ras association domain-containing protein 1A (RASSF1A) to promote hypoxia-signaling to PASMC in PAH thereby likely conferring a cancer-like PASMC phenotype (168). This evidence concerns the gene SERPINE1 and pulmonary arterial hypertension.