TNF and rheumatoid arthritis: Figures 4 and 5 show that the combined treatment of IL-27 and TNF-α or IL-1β resulted in additive or synergistic up-regulation of ICAM-1 and VCAM-1 expression and the release of CXCL9 and CXCL10 of RA-FLS (all P < 0.01).