Animal-free Recombinant Human IL-1 beta expressed in human 293 cells has a very high activity with a typical EC50 of ≤0.1 ng/mL using a bioassay to measure stimulation of the proliferation of mouse D10S cells. In comparison with the E. coli expressed protein, IL-1 beta is 50% more potent promoting human CD4+ T cell differentiation into Th17 cells. This cytokine is important for inflammatory responses. It is also involved in a variety of cellular activities which includes cell differentiation, proliferation, and apoptosis. It is produced in a serum-free, chemically defined media.