Charles W. Flexner, M.D., is Professor of Medicine (Clinical Pharmacology and Infectious Diseases), Professor of Pharmacology and Molecular Sciences in the Johns Hopkins University School of Medicine, and Professor of International Health in the Johns Hopkins University Bloomberg School of Public Health. Dr. Flexner is an expert on the basic and clinical pharmacology of drugs for HIV and related infections. His scientific contributions include work on pharmacokinetic enhancement, medication adherence, and dosing frequency. He directs the Long Acting/Extended Release Antiretroviral Research Resource Program (LEAP; www.longactinghiv.org), and is Co-Principal Investigator of the Johns Hopkins University Baltimore-Washington-India Clinical Trials Unit. Dr. Flexner is Chair of the ACTG Antiretroviral Treatment Strategies Translational Sciences Group and serves on the WHO Clinical Guidelines Development Group for Treatment and Prevention of HIV in Adults, Adolescents, and Children.