We obtained lung tissues from our rat model of rI/R-induced ALI, and used these tissues for hematoxylin and eosin (H&E) staining, immunohistochemical analysis of myeloperoxidase, immunofluorescence analysis of F4/80, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) analysis. The gene discussed is MPO; the disease is acute respiratory distress syndrome.