History of Developing Acute Promyelocytic Leukemia Treatment and Role of Promyelocytic Leukemia Bodies

Simple Summary Acute Promyelocytic Leukemia (APL) was the most aggressive form of leukemia, historically associated with massive and rapid mortality. However, empirical clinical advancements and in-depth mechanistic exploration have now transformed APL into the most curable form of leukemia, culminating with the ATRA/ATO combination, which cures up to 98% APL patients. This review recapitulates a three-decade journey which led to the development of this groundbreaking treatment, through several paradigm shifts to explain its scientific underpinnings.Abstract The story of acute promyelocytic leukemia (APL) discovery, physiopathology, and treatment is a unique journey, transforming the most aggressive form of leukemia to the most curable. It followed an empirical route fueled by clinical breakthroughs driving major advances in biochemistry and cell biology, including the discovery of PML nuclear bodies (PML NBs) and their central role in APL physiopathology. Beyond APL, PML NBs have emerged as key players in a wide variety of biological functions, including tumor-suppression and SUMO-initiated protein degradation, underscoring their broad importance. The APL story is an example of how clinical observations led to the incremental development of the first targeted leukemia therapy. The understanding of APL pathogenesis and the basis for cure now opens new insights in the treatment of other diseases, especially other acute myeloid leukemias.