Although advances in hematology have led the way in many fields of basic and translational biomedical research, hematologic diseases remain major threats to public health. For example, the prognosis for many hematologic malignancies continues to be poor. Current treatments are inadequate to support a normal lifestyle for most patients with sickle cell disease. In the U.S., at least 500,000 venous thromboembolic events, 1 million heart attacks and 150,000 stroke deaths occur each year. At the same time, opportunities for hematology research have never been more promising, and converting these opportunities into medical advances will depend upon training the next generation of basic and translational hematology researchers. The Molecular Hematology train- ing program proposes to fill this need for 5 predoctoral and 8 postdoctoral trainees per year. Predoctoral Ph.D. and M.D./Ph.D. students follow the curriculum of the Washington University graduate school. After passing their qualifying examination, they enter the laboratory of participating faculty Mentors for 3-4 years of laboratory re-search to complete their dissertation. Postdoctoral Ph.D. trainees from around the world apply to participating laboratories; postdoctoral M.D. and M.D./Ph.D. trainees usually have completed the clinical training component of a Hematology-Oncology fellowship program at Washington University or elsewhere. The duration of postdoc-toral training depends on prior experience. Those with Ph.D. or M.D./Ph.D degrees typically conduct research for 2-3 years before transitioning to an independent research position, whereas those with an M.D. degree may benefit from 3-4 years of postdoctoral training. Trainees receive intensive mentoring and career counseling, and participate in coursework, journal clubs, and seminars. The major facilities of the program consist of ~80,000 square feet of fully-equipped laboratory space that house the Divisions of Hematology and Oncology, as well as extensive institutional resources for genome sequencing, immune monitoring, informatics, animal studies, and patient-oriented clinical research. The research topics available to trainees reflect the multidisciplinary expertise of the participating Mentors and include: pathogenesis of hemorrhagic and thrombotic disorders; regulation of blood coagulation and fibrinolysis; gene therapy of hemophilia and lysosomal storage diseases; phosphoinosi-tide metabolism and cell signaling pathways; mechanisms of hematopoiesis; telomerase defects in bone marrow failure syndromes; molecular basis for protein trafficking in mammalian cells; role of platelets and angiogenesis in metastasis; biology of human immunodeficiency and leukemia viruses; epithelial morphogenesis; pathogene-sis of leukemia, myelodysplastic syndrome, myeloproliferative neoplasms, and congenital neutropenia; cell cycle control; programmed cell death in development and malignancy. Completion of this program will prepare talented trainees for car...