CD4 and Sepsis: Here, we report that Nrp‐1 and TGF‐β1 stimulate the stability of CD4+CD25+ Tregs in the presence of LPS and that Nrp‐1 contributes to the activity of recombinant TGF‐β1 by the regulation of TGF‐β1/Smads cell signaling in sepsis.