Dr. Marr is a Professor of Medicine and Oncology and serves as the Director of the Transplant and Oncology Infectious Diseases Program at Johns Hopkins. She serves as Vice Chair of Medicine for Innovation in Healthcare Implementation. The overarching theme of Dr. Marr’s research program is to reduce infectious morbidity in medically immunosuppressed hosts, by using a bi-directional translational approach, integrating laboratory and clinical trials to develop and optimize diagnostic tools and prevention strategies. Studies have focused specifically on pulmonary fungal infections that have significant morbidity. Her laboratory made pivotal observations describing innate risks for pulmonary fungal infections in transplant patients and mechanisms of host-pathogen interaction, advancing personalized strategies to prevent transplant–associated infection. Her group discovered a new fungal pathogen now recognized as a widely distributed drug-resistant organism (Aspergillus lentulus). Current laboratory efforts are focused on optimizing diagnostics, including immunologic methods to detect both active and latent infections. Her work was instrumental in optimizing current commercially available tests, and new technology has led to establishment of a start-up company focused on developing tests and drugs to prevent fungal infections. Altogether, Dr. Marr’s efforts have advanced our understandings of pulmonary fungal infections and have resulted in important diagnostic tools and drugs used in practice today. In 2015, she was named by Thomson Reuters as one of the “World’s Most Influential Scientific Minds”, based on 11-year citation data.