DPP4 and rheumatoid arthritis: Because high FABP4 expression was observed in synovial M1-polarized macrophages in RA patients and the RA mouse model, BMS309403 and anagliptin (dipeptidyl peptidase 4 inhibitors) were administered to TSC1KO mice for 4 and 8 weeks to inhibit endogenous FABP4 after AIA surgery.