As shown in Fig. 4a, the percentages of tissue IL-9-producing CD4(+) T cells in the control group were significantly lower than that in the sepsis group (0.22%±0.04% vs. 1.02%±0.07%, P < 0.001) or the sepsis+IL-9 group (0.22%±0.04% vs. 1.57%±0.10%, P < 0.001). Here, CD4 is linked to Sepsis.