RS 09 is a peptide agonist of toll-like receptor 4 (TLR4).1 It activates NF-κB in a concentration-dependent manner in a secreted alkaline phosphatase (SEAP) assay using TLR4-expressing HEK293 cells and induces NF-κB nuclear translocation in the same cells. It also induces cytokine secretion from RAW 264.7 cells. RS 09 (25 µg/animal) acts as an adjuvant in mice vaccinated with a KLH-conjugated X-15 antigen, with no antibodies produced in mice receiving RS 09 without the antigen.WARNING This product is not for human or veterinary use.