PI3 and acute respiratory distress syndrome: As shown in Table 2, both the ARDS samples (n = 67, 48-hour of ARDS diagnosis) and the ICU control samples (n = 63, 48-hour of ICU admission) had significantly elevated plasma levels of PI3, SLPI, and HNE (P<10−6 for all comparisons, two sample t-tests), as compared with the reference plasma samples from healthy individuals (n = 28).