CD4 and acute respiratory distress syndrome: The prevalence of Th2 (CD4+ IL-4+/CD4+ T cells) in lung was significantly higher in ALI 24 h group than that in ALI 6 h group (ALI 6 h group: 12.3 ± 0.85%, ALI 24 h group: 14.7 ± 0.47%, P = 0.009, Supplementary Fig. S2).