CD4 and Sepsis: As shown in Figure 5(b), the deficiency of Vit C significantly increased the apoptotic rate of splenic CD4+CD25− T cells of Gulo−/− mice (p < 0.01); however, treatment with parenteral Vit C after CLP decreased the apoptotic rate of CD4+CD25− T cells of WT mice and Gulo−/− mice with sepsis (p < 0.05 or 0.01).