An external validation study101 of existing gene expression signatures for anti-TNF treatments in RA was performed using a genome-wide expression profiling to validate eight previously reported signatures predicting anti-TNF therapy outcome (Lequerré et al.77—20 and 8 genes, Stuhlmüller et al.87—82, 11 and 3 genes, Julia et al.86—8 genes, Tanino et al.85—8 genes and Sekiguchi et al.83—18 genes) on whole blood of 42 RA patients before treatment with infliximab or adalimumab. This evidence concerns the gene TNF and rheumatoid arthritis.