Children with oligoarticular juvenile idiopathic arthritis initially present with only a few arthritic joints (less than 5). Some children with oligo JIA will continue to have mild disease (oligoarticular course) and others will go onto develop more severe disease with more arthritic joints (polyarticular course) and eye inflammation (uveitis). As pediatric rheumatologists, we would like to use biomarkers from the peripheral blood to identify which patients are at greatest risk for severe disease. If we can identify at risk patients, we can try to prevent disease extension with medications. This study will allow us to collect and analyze blood samples from oligo JIA patients in an effort to answer these questions.