CTLA4 and Sepsis: It was found that sepsis could obviously upregulate the negative immunoregulation of CD4+CD25+Tregs and Nrp-1highCD4+CD25+Tregs, especially Nrp-1highCD4+CD25+Tregs, but downregulated the negative immunoregulation of Nrp-1lowCD4+CD25+Tregs, which correlated with the expressions of Foxp-3/CTLA-4/TGF-βm+ and the apoptotic ability, as well as the secretion of IL-10 and TGF-β.