FABP4 and rheumatoid arthritis: Adipocyte-related genes (FABP4 and PPARγ) were significantly increased (P < 0.05) after differentiation into adipocytes compared to the undifferentiated state, but the levels of FABP4 in E- and L-RA-SF-MSCs (246.1±1.1 and 294.5±1.1) were significantly (P < 0.05) lower than in C-SF-MSCs (868.5±0.9).