Paul E. Sax, M.D., is Clinical Director of the Division of Infectious Diseases at Brigham and Women’s Hospital and Professor of Medicine at Harvard Medical School, Boston, MA. He is actively involved in HIV research, clinical practice, and teaching. His research interests include clinical trials of new antiretroviral therapies, the cost-effectiveness of HIV management strategies, and the complications of antiretroviral treatment. Dr. Sax is Principal Investigator of the Brigham and Women’s Hospital AIDS Clinical Trials Unit and a member of the Cost Effectiveness of Preventing AIDS Complications (CEPAC) Research Group. He  writes the NEJM Group HIV and ID Observations blog. Dr. Sax is Editor-in-Chief of Open Forum Infectious Diseases and HIV Section Editor for UpToDate.