Spyros Artavanis-Tsakonas

Spyros Artavanis-Tsakonas is the discoverer of the Notch signaling pathway and has made seminal contributions to understanding its role in cancer as both an oncogene and tumor suppressor depending on cellular context. His laboratory cloned the Notch receptor and defined the proteolytic cascade involving ADAM metalloproteases and gamma-secretase that releases the Notch intracellular domain to activate target gene transcription. He demonstrated that activating NOTCH1 mutations drive T-cell acute lymphoblastic leukemia while loss-of-function Notch mutations promote squamous cell carcinomas. His work established the context-dependent nature of Notch signaling in cancer that has challenged simple therapeutic targeting approaches.