We hypothesised that the pretreatment TNFα level in the synovium might be related to clinical efficacy, where TNFα blocking therapy could be most effective in patients with high pretreatment TNFα levels, as previously suggested in a small pilot study.7 In a prospective study we obtained arthroscopic synovial tissue samples from 143 patients with RA prior to initiation of infliximab therapy. This evidence concerns the gene TNF and rheumatoid arthritis.