Dr. Joep Lange and his partner Jacqueline van Tongeren were among the Dutch passengers lost on Maylasia Airlines Flight 17. Dr. Lange was a Professor of Medicine at the Academic Medical Center of the University of Amsterdam, the Head of the Department of Global Health, the Executive Scientific Director of the Amsterdam Institute for Global Health and Development, and the Chair of its Steering Committee. He was an international leader in HIV/AIDS research, previously serving as the President of the International AIDS Society from 2002-2004, and the Chief of Clinical Research and Drug Development for the Global Programme on AIDS of the World Health Organization in Geneva from 1992-1995. He was a pioneer in early HIV drug development, leading pivotal trials in the early days of the global epidemic, and pioneered some of the approaches aimed at curing HIV infection. He was a tireless advocate for patients, and was among the first of the world's major leaders in the field to recognize and implement programs and strategies to bring the advances in HIV treatment to the developing world. He founded one of the first major research conferences to focus on HIV/AIDS in resource limited settings, the International Workshop on HIV Treatment, Pathogenesis and Prevention Research in Resource Limited Settings (INTEREST). He and his partner, Jacqueline, worked tirelessly developing insurance strategies designed to bring sorely needed drugs to resource limited settings, implementing some of the nascent programs, including one of the most important programs in Thailand (HIVNAT) that preceded the now larger and highly applauded efforts of the Global Fund for HIV, TB and Malaria and the President's Emergency Plan for AIDS Relief (PEPFAR). Joep and Jacqueline were deeply committed, kind and wonderful colleagues and friends who will be sorely missed in the world community of HIV/AIDS research and care. It is difficult to express the depth of our sorrow at their loss.