Third, an obvious increase in osteoclasts was observed in RA mice that were treated with rmFABP4, and a significant decrease in osteoclasts was observed in RA mice that were administered BMS309403, which indicates that FABP4 might play a role in regulating osteoclast activity, but the specific mechanism needs to be further assessed. The gene discussed is FABP4; the disease is rheumatoid arthritis.