Indeed, a significant surface expression of TLR2 on CD4+CD28null T cells has only been found in patients with AS, but not in patients with PsA and RA (Figure 1b), which is consistent with an earlier histological study in RA that did not find TLR2 on CD3+ T cells in the synovial tissue [32]. This evidence concerns the gene TLR2 and rheumatoid arthritis.