CTLA4 and Sepsis: Figure 3(c) shows that CD4+Foxp3+CTLA4+ TReg cells increase in frequency during sepsis as compared to sham (sham = 5.26 ± 0.81%, CLP = 9.31 ± 0.88%; p = 0.002) and that SIRT1 inhibition significantly reduces CD4+Foxp3+CTLA4+ TReg cell subpopulations (Figure 3(c)). The absolute cell counts of all the measured TReg subpopulations also decreased, but without statistical significance (Figure 3(d)).