The percentage of CD4+ T cells in lung was significantly higher in ALI 24 h group than that in ALI 6 h group (ALI 6 h group: 47.1 ± 2.1%, ALI 24 h group: 52.3 ± 2.3%, P = 0.044, Fig. 3). This evidence concerns the gene CD4 and acute respiratory distress syndrome.