Interleukin 12 (IL-12) is a pro-inflammatory cytokine with a molecular weight of 70 kDa composed of two subunits, IL-12p35 (35 kDa) and IL-12p40 (40 kDa) . IL-12p40 is induced in excess over the other subunits of IL-12 and IL-23 and can exist in a monomeric or homodimer form.