TIMP1 and acute respiratory distress syndrome: Both the ARDS and non-ARDS groups showed significantly higher plasma levels of MMP-9 and TIMP-1 compared to HD (MMP-9: p < 0.0001 and p = 0.0002, respectively; TIMP-1: p < 0.0001 and p < 0.0001, respectively) (Figure 1A and Figure 1B, respectively) (Table 2).