As shown in Figure 6, TLR2 expression (calculated as percentage of CD14+ monocytes expressing TLR2) was significantly correlated with IL-6 concentration following stimulation with 10 μg/mL of peptidoglycan (r = 0.611, P = 0.001) in RA patients, but not significant in healthy volunteers (r = 0.449, P = 0.193). Here, TLR2 is linked to rheumatoid arthritis.