[Feature] The Avenger
David Fajgenbaum was in his third year of medical school at the University of Pennsylvania (UPenn) 6 years ago, on an obstetrics-gynecology rotation, when he was first hit by night sweats, fatigue, and weight loss. His eventual diagnosis: a deadly form of Castleman disease, a rare immune disorder for which knowledge was in depressingly short supply. So Fajgenbaum decided to dedicate himself to taking down this disease. He abandoned plans to become an oncologist, skipped medical residency, and enrolled in business school instead—building a powerhouse network of hundreds of physicians, researchers, and drug company employees around the world to help him decipher Castleman. He co-authored papers with his doctor, wrote a case study about himself, proposed a new model of the disease, and currently coordinates a dozen Castleman studies from his small office at UPenn, where he is an assistant professor. Author: Jennifer Couzin-Frankel