This project is a genome-association-study on patients with rheumatoid arthritis (RA) and controls from northern Sweden. We are following the disease consecutively and collecting information on the disease progression and development e.g development of comorbidity and also response to treatment. We will relate this clinical progression to different genotypes and also compare the distribution of alleles for. Certain SNPs in comparison to controls. By these analyses we hope to identify different clinical phenotype that is with different progression course of the disease related to different genotypes. Furthermore, we will also relate the response to therapy in RA patients to certain genetic markers. The RA patients are treated with conventional disease modifying anti-rheumatic drugs (DMARDs) particularly methotrexate, that is the anker drug but also with biological DMARDs. The response to treatment is highly variable, which could be genetically related and also the development of side effects.