It is with great sadness that we mark the passing of Dr. Charles Boucher. As one of the smartest scientists in the HIV field, Charles made major contributions to the areas of HIV virology and drug resistance. He had a passion for addressing scientific challenges to help improve the lives of patients worldwide. We were very fortunate to count him as a colleague and friend in our consortium and shared a common goal to advancing HIV science, delivering innovations to people who need it most, and help bring an end to AIDS. His intellectual contribution, collaborative spirit, and enthusiasm for our mission will leave a tremendous void. Our thoughts are with his family and with his team and colleagues at the Erasmus University.