Pre-cancer and cancer can begin when stressed blood-forming stem cells lose their normal controls. Catriona Jamieson, M.D., Ph.D., UC San Diego, explains how inflammation-linked editing enzymes, repetitive elements in the genome, and stem cell stress shape the progression from myeloproliferative neoplasms to acute myeloid leukemia. Jamison examines how spaceflight accelerates stem cell aging, how some astronauts mobilize a resilient regenerative stem cell population, and how tumor organoids in space help reveal drug responses by activating the enzyme ADAR1. This work helps explain how cancer starts, why it can return, and how space-based research may speed the development of therapies that stop malignant stem cells before disease advances. Series: "Stem Cell Channel" [Health and Medicine] [Science] [Show ID: 41473]