Product Description: Interleukin-4 (IL-4) is an immunomodulatory cytokine that functions to induce naive helper T cells to differentiate into type 2 T helper (Th2) cells. Th2 cells subsequently produce more IL-4 in a positive feedback loop. IL-4 also promotes immunoglobulin IgG to IgE isotype switching on B cells. IL-4 binds the IL-4Rα receptor to activate STAT6 signaling.