CTLA4 and Sepsis: Compared with the control group, sepsis significantly upregulated the expression of Foxp-3/CTLA-4/TGF-βm+ on CD4+CD25+Tregs and Nrp-1highCD4+CD25+Tregs (P < 0.01), but the expression of Foxp-3/CTLA-4/TGF-βm+ on Nrp-1lowCD4+CD25+Tregs was significantly downregulated (P < 0.01).