Before the biologic era, treatment of juvenile idiopathic arthritis (JIA) was often highly unsatisfactory, with children forced to endure the ill effects of lifelong disease, including pain and stiffness, disability, and even increased risk of mortality. Thanks in large part to improved understanding of the underlying pathophysiology of the disease, multiple new biologic agents have been developed and applied to these disorders, with remarkable effects. However, much information remains to be learned about applying particular therapies to the distinct categories of JIA, and there is still considerable room for improvement in individual patients. © 2013 Elsevier Inc.