IL-23-induced osteoclastogenesis from cultured human peripheral blood mononuclear cells. A variable concentration of recombinant human (rh)IL-23 (0.01, 0.1, or 1 ng/ml) was present during the first 3 days (days 0 to 4). After 10 days, osteoclasts positive for anti-vitronectin receptor antibody were counted. Data are expressed as means and SD for triplicate cultures. Experiments were repeated three times with similar, significant results; #P = 0.002 (Student's t test).