David Fajgenbaum, MD, MBA, MSc, is the co-founder and Executive Director of the Castleman Disease Collaborative Network (CDCN) and one of the youngest individuals to be appointed to the faculty at Penn Medicine, where he is an Assistant Professor of Medicine in Translational Medicine & Human Genetics, Founding Director of the Center for Study & Treatment of Castleman & inflammatory Lymphadenopathies (CSTL). An NIH-funded physician-scientist, he has dedicated his life to discovering new treatments and cures for deadly disorders like idiopathic multicentric Castleman disease (iMCD), which he was diagnosed with during medical school. As common as ALS and more deadly than lymphoma, iMCD involves the immune system attacking and shutting down the body's vital organs such as the liver, kidneys, bone marrow, and heart. After spending months hospitalized in critical condition, having his last rites read, and having four deadly relapses, he is now in his longest remission ever thanks to a treatment that he identified in the lab.