TNF and Sepsis: A sepsis attenuation assay in human blood was performed to determine whether the immunogenicity of the mRNA would counteract the intended anti‐inflammatory effects of IL‐10 overexpression (Figure 5e): Freshly collected blood from healthy donors was stimulated with bacterial endotoxin/lipopolysaccharide (LPS) to induce TNF‐α secretion, as is the case in sepsis.[37, 38] IL‐10 is known to reduce TNF‐α production by monocytes.[39] Therefore, supernatants from IL‐10 mRNA‐transfected BMSCs were added to LPS‐stimulated blood.