SERPINE2 and neoplasm: However, serpinE1 (or plasminogen activator inhibitor-1, PAI-1) has been reported to promote angiogenesis and to induce tumor cell migration [24-26] while serpinE2 (or protease nexin-1, PN-1) appears to enhance the invasive potential of pancreatic [27], breast [28] and lung cancer cells [29].