SERPINE2 and idiopathic pulmonary fibrosis: Through its anti-thrombotic and anti-fibrinolytic activities, PN-1 is a key regulator of vascular responses to injury6 and is overexpressed in numerous diseases where an important inflammatory reaction takes place, like atherosclerosis7,8, scleroderma9, or idiopathic pulmonary fibrosis (IPF)10.