TLR2 and Arthritis: In TLR2/C-3 double-deficient mice, synovial infiltrate was significantly decreased in comparison with control (4.0 ± 0.65 in control mice [n = 5] versus 1.9 ± 0.62 in TLR2/C-3 double-deficient mice [n = 5] on day 25 after arthritis onset; P < 0.05) (Fig. 4b).