Neutrophil elastase (NE) degrades constituent proteins of lung tissue, such as elastin (9), collagen (9), and E-cadherin (10), and acts as an exacerbating factor in acute and chronic pulmonary diseases, including acute respiratory distress syndrome (11), cystic fibrosis (12), and chronic obstructive pulmonary disease (13). Here, ELANE is linked to acute respiratory distress syndrome.