PAIN is the official journal of the International Association for the Study of Pain (IASP), and presents original research on the nature, mechanisms, and treatment of pain. It provides a forum for the dissemination of multidisciplinary research in the basic and clinical sciences. PAIN continues to be the premier journal in the field of anesthesiology, attaining an Impact Factor in 2013 of 5.836 and a five-year mark of 6.341, the top ranking during that period.