MMP2 and acute respiratory distress syndrome: The levels of RAGE, TGF-β1, MMP2, and MMP9 in the ARDS + SIS3 group were 68 ± 4.98, 55.20 ± 4.71, 49.20 ± 3.90, and 28.40 ± 4.48% (for sera) and 64.30 ± 4.37, 58.80 ± 3.04, 42.70 ± 3.49, and 47.40 ± 6.38% (for BALF), which were lower than those in the ARDS group (P < 0.05 in all cases, Figures 6(a)–6(d)).