TIMP-1 concentrations were slightly lower in the ARDS subjects compared to controls (mean±SEM = 113±15 ng/mg vs.144±27 ng/mg, respectively; p = 0.43), contributing to higher MMP-9:TIMP-1 activity ratios in ARDS subjects compared to controls (mean±SEM = 2.7±0.6 vs. 1.4±0.5, respectively; p = 0.039). This evidence concerns the gene TIMP1 and acute respiratory distress syndrome.