In this study, we demonstrated, for the first time, that administration of the PEP-NASP fusion protein effectively protected mice against LPS-induced ALI, with significantly attenuated pulmonary polymorphonuclear (PMN) infiltration, decreased lung MPO activity, suppressed inflammation, reduced BALF protein content, and ameliorated lung pathological changes. The gene discussed is NASP; the disease is acute respiratory distress syndrome.