In the study, significantly higher NE680 fluorescent signal was observed in mice with lipopolysaccharide/fmet-leu-phe (LPS/fMLP) induced acute lung injury (ALI) than in healthy controls because intranasally administered LPS and fMLP act synergistically to cause lung inflammation via massive neutrophil infiltration and degranulation [14–16], leading to increased NE activity. Here, FPR1 is linked to acute lung injury.