An inhibitor of the gp130-IL-6/IL6Ra protein-protein interaction binds to gp130 (Kd 7.4 UM) and selectively inhibits IL-6-induced STAT3 phosphorylation over leukemia inhibitor factor- or phorbol 12-myristate 13-acetate-induced STAT3 phosphorylation in HepG2 cells at 10 30 or 100 UM reduces IL-6-induced increases in the viability of GM-CSF-starved TF-1 leukemia cells at 10 to 1000 nM inhibits the LPS- and AGE-induced increases in mRNA encoding Rankl as well as inhibits increases in the phosphorylation levels of gp130 Stat3 and Jak2 in mouse MC3T3-E1 osteoblasts at 100 nM decreases joint and paw swelling as well as serum levels of COMP SAP and anti-collagen II antibodies in a mouse model of collagen-induced arthritis at 0.25 mg/kg per day reduces bone resorption height and volume in a rat model of type 2 diabetes peri-implantitis induced by LPS P. gingivalis and a high-fat and high-sUGar diet at 0.23 mg/kg per day p.o.