We measured sIL7R serum concentrations in sera from DMARD-resistant RA patients prior to initiation of infliximab therapy (65), and found significantly higher concentrations in 18 poor- compared to 57 good- and moderate-responders (predictive positive and predictive negative values in predicting response to therapy were 87 and 71%, respectively). The gene discussed is IL7R; the disease is rheumatoid arthritis.