TNF and rheumatoid arthritis: De Rycke et al. showed increased TLR4 expression in peripheral blood mononuclear cells from patients with AS, as well as increased TLR2 and -4 expression in the inflamed synovium of patients with SpA (including PsA, AS and undifferentiated spondyloarthritis) compared with osteoarthritis or RA synovium, which was sharply reduced by TNFa blockade [148].