Abstract: The invention relates to an array comprising oligo- or poly-nucleotide probes, immobilized on a solid support. The array is characterized in that, sequences of a selection or all of the selective monocytic macrophagic genes given in Tables 1-6 are bonded on the surface. The array permits the diagnosis of rheumatoid arthritis and other chronic inflammatory diseases, a corresponding analysis of the efficacy of treatment and the monitoring of side-effects with the anti-tumor necrosis factor (TNF) therapy and thus permits the selection of the most effective therapy for each patient with rheumatoid arthritis. The invention further relates to a nucleic acid array for the prognosis and development of novel anti-TNF type medicaments and such medicaments with a mode of action in said regulatory circuit.