IL-12 is a 75-kDa heterodimeric cytokine composed of two covalently linked p35 and p40 chains .
il-12 is a 75-kda heterodimeric cytokine composed of two covalently linked p35 and p40 chains .
B-protein_molecule O O B-protein_molecule I-protein_molecule I-protein_molecule O O O O O O O O O O