The prevalence of Th2 (CD4+ IL-4+/CD4+ T cells) in lung was significantly higher in ALI 24 h group than that in normal control group (Con group: 9.8 ± 0.64%, ALI 24 h group: 14.7 ± 0.47%, P = 0.0005, Supplementary Fig. S2). The gene discussed is CD4; the disease is acute respiratory distress syndrome.