Description_x000D_ Biochem/physiol Actions_x000D_ Interleukin-4 is a lymphokine with profound effects on the growth and differentiation of immunologically competent cells. IL-4 is also known as B cell stimulatory factor-1 (BSF-1), T cell growth factor-2 (TCGF-2) and mast-cell growth factor-2 (MCGF-2). Inhibits VEGF-induced and bFGF-induced angiogenesis. IL-4 is a complex glycoprotein released by a subset of activated T cells. Human and mouse IL-4 share 50% amino acid sequence homology, but their biological actions are species-specific._x000D_ Interleukin-4, a lymphokine with profound effects on the growth and differentiation of immunologically competent cells, inhibits VEGF-induced and bFGF-induced angiogenesis. Human and mouse IL-4 share 50% amino acid sequence identity, but their biological actions are species-specific._x000D_ Physical form_x000D_ Lyophilized from a 0.2 μm filtered solution in phosphate buffered saline containing 0.25 mg bovine serum albumin._x000D_ Analysis Note_x000D_ The biological activity of recombinant rat IL-4 was measured by its ability to stimulate proliferation of rat splenocytes.