Affecting approximately one percent of the adult world population, rheumatoid arthritis is the most common inflammatory joint disease. Due to its positive benefit-risk ratio, Methotrexate (MTX) is first-line therapy in rheumatoid arthritis. Although the drug is very effective, the large inter-patient variability regarding efficacy and frequency of adverse events are major drawbacks. The author describes a randomized, double-blinded controlled clinical trial, investigating the role of methotrexate polyglutamates as a marker for clinical response. Based on the detailed analysis of...