The IL-12 p40 subunit, or interleukin-12 beta subunit, is the 40 kD cytokine receptor-like subunit of the heterodimeric cytokines IL-12 and IL-23. IL-12 is involved in the differentiation of naive T cells into Th1 cells and the growth and function of T cells. Both IL-23 and IL-12 can activate the transcription activator STAT4 and stimulate the production of interferon-gamma (IFNG). Equine IL-12 p40 Recombinant Protein is purified interleukin-12 p40 produced in yeast.