Leukemia, the blood cancer, is a group of hematopoietic malignancies. Many types of leukemia are associated with poor outcome. Unfortunately, during the past few decades, the first-line leukemia therapy has long been traditional chemotherapy with high cytotoxicity and low selectivity, such as the "7+3" strategy, i.e., a combination of cytarabine and doxorubicin. Side effects of such intensive chemotherapies are often severe, especially in older patients. Therefore, it is an urgent need to understand the mechanisms of leukemia, and develop novel targeted therapy based on such comprehension. In this work, Jiang's group first found through drug screening that opioid receptor agonists,...