CD4 and Sepsis: The serum percentages of IL-9-producing CD4(+) T cells of the sepsis+IL-9 group were significantly higher than that of the sepsis group (3.53%±0.90% vs. 1.58%±0.41%, P =0.001) or the sepsis+sh-IL-9 group (3.53%±0.90% vs. 0.80%±0.02%, P < 0.001).