IL18 and rheumatoid arthritis: Crucially, although no difference in the number of macrophages between RA and non‐RA patients was observed (Figure 1A), the absolute level of IL‐18 and TNF expression in aortic adventitia was higher in RA patients (Figures 1B and C) compared with non‐RA controls (P = 0.03 and P = 0.02, respectively).