Timothy J. Ley, MD

MGI Associate Director

Professor of Medicine

Dr. Ley is a hematologist, oncologist and cancer biologist. For many years, the Ley lab has used mouse models of acute myeloid leukemia (AML) to establish key principles of AML pathogenesis. The lab established that the initiating event for Acute Promyelocytic Leukemia (APL) is the PML-RARA fusion gene created by the t(15;17) that is found in nearly all patients with this disease. The roles of cooperating mutations and the cellular milieu for APL pathogenesis have also been established. In collaboration with the McDonnell Genome Institute at Washington University, the investigators of the Genomics of AML Program Project Grant (PPG- TJ Ley, PI) sequenced the first human cancer genome (a patient with AML) and the first mouse cancer genome (from the mouse model of APL) and have discovered several new recurrent mutations that are important for AML pathogenesis and outcomes, including recurring mutations in DNMT3A and IDH1/2, among many others. These data are now being correlated to RNA expression, DNA methylation, histone modifications and chromatin structure, protein abundance and modification, and clinical datasets. Mouse models of epigenetic modifier mutations in AML are now being created and analyzed. These efforts will hopefully lead to new tests to better establish prognosis, and new approaches for the therapy of patients with this disease.

Dr. Ley is the Lewis T. and Rosalind B. Apple Professor of Oncology in the Department of Medicine, and is chief of the Section of Stem Cell Biology in the Division of Oncology. He is also Director of the Embryonic Stem Cell Core at the Siteman Cancer Center, and Professor of Genetics. Dr. Ley received his BA degree from Drake University in 1974, and his MD from Washington University School of Medicine in 1978. He did his internship and residency in Medicine at Massachusetts General Hospital, was a Clinical Associate at the National Heart, Lung, and Blood Institute, a Hematology-Oncology Fellow at Washington University Medical Center, and a Senior Investigator at the National Heart, Lung, and Blood Institute before moving to Washington University in 1986.

In 2015, Dr. Ley was named to the National Cancer Advisory Board by President Barack Obama. The board advises the U.S. Secretary of Health and Human Services, the director of the National Cancer Institute (NCI), and the president on the nation’s cancer program and reviews proposals awarded by the NCI. Ley is an elected member of the National Academy of Medicine and of the American Academy of Arts and Sciences. He also is a past president of the American Society for Clinical Investigation and was chair of the Board of Scientific Counselors for the National Human Genome Research Institute.

Division of Oncology bio

Dr. Ley’s publications