PECAM1 and acute respiratory distress syndrome: The data showed reduced CD31 (day 2 = 1.83 ± 0.17, p = 0.0451; day 7 = 1.2 ± 0.2, p = 0.0256) and increased Casp-3 (day 2 = 2.8 ± 0.31, p = 0.0001; day 7 = 3.2 ± 0.37, p = 0.0001) staining in the ARDS-RL group compared with the CTRL group at both endpoints of day 2 (CD31 = 3.13 ± 0.3; Casp-3 = 0.0) and 7 (CD31 = 3.13 ± 0.3; Casp-3 = 0.0).