Next, to confirm that variable GADD45a expression levels are associated with variable susceptibility and severity of ALI in vivo, WT, GADD45a heterozygous mice (GADD45a+/−) and GADD45a−/− mice were subjected to VILI challenge (VT 40 ml/kg, 4 h) and BAL fluid was collected for analysis. This evidence concerns the gene GADD45A and acute respiratory distress syndrome.