Jun J. Yang

Jun J. Yang, PhD is a Member of the Department of Pharmaceutical Sciences and Associate Member of the Department of Oncology at St. Jude Children's Research Hospital. He is an internationally recognized leader in the pharmacogenomics of ALL therapy and germline genetics of leukemia predisposition, with his research bridging fundamental pharmacology with direct clinical application in childhood ALL. Dr. Yang's laboratory has extensively characterized inter-individual variation in thiopurine metabolism (6-mercaptopurine, thioguanine), the cornerstone drugs in ALL maintenance therapy, identifying genetic variants (TPMT, NUDT15) that predict drug toxicity and require dose adjustment in diverse patient populations. His discovery that NUDT15 variants are a major determinant of thiopurine toxicity in East Asian and Hispanic patients — populations in whom TPMT-based dosing fails — has been immediately translated into clinical practice and updated ALL treatment guidelines worldwide. Dr. Yang has also been a pioneer in studying germline genetic predisposition to ALL, identifying inherited variants in genes including IKZF1, ARID5B, CEBPE, and TP53 that explain a significant proportion of ALL risk across ethnic groups. His work on the genomics of Down syndrome ALL has defined the molecular basis for the hypersensitivity to methotrexate and other agents observed in this population, directly informing treatment modifications that have improved outcomes.