Some signaling molecules associated with neutrophil and platelet activation, ECM remodeling or coagulation cascade (e.g., EGFR, CD44, CD63, CD177, CTSG, MMP8, MMP9, ELA2, MPO, pro-thrombin, fibrinogen, or fibronectin) were only found to be significantly upregulated in WT, but not in miR-21 KO mice with ALI. Here, MPO is linked to acute respiratory distress syndrome.