John Choi, M.D., Ph.D., a professor in the Division of Laboratory Medicine and director of the Flow Cytometry Laboratory, is retiring from the Department of Pathology, effective June 30, 2026.
Choi joined the department in 2020 from St. Jude Children’s Research Hospital Department of Pathology in Memphis, Tennessee, where he directed Hematopathology, Hematology, Immunopathology, and Special Hematopathology.
“Dr. Choi’s internationally recognized expertise in minimal residual disease transformed patient care at UAB and helped shape global diagnostic standards through his significant contributions to the World Health Organization’s Classification of Haematolymphoid Tumours, the gold-standard diagnostic framework for hematologic malignancies,” said Sixto Leal, M.D., Ph.D., Jay M. McDonald Endowed Professor in Experimental Pathology and director of the Division of Laboratory Medicine.
Choi completed his residency in anatomic pathology and a fellowship in hematopathology at the Hospital of the University of Pennsylvania. Upon completion, he joined the Department of Pathology there as a hematopathologist. After three years, he was recruited and moved 100 yards to establish a pediatric hematopathology program at the Children’s Hospital of Philadelphia. After 10 years and successfully building a highly regarded pediatric hematopathology service, Choi was recruited to St. Jude Children’s Research Hospital in Memphis, where he maintained a top pediatric hematopathology service and established clinical flow-based minimal residual disease assays for national acute lymphoblastic leukemia and acute myeloid leukemia protocols. After 9 years, he was recruited to UAB.
“Dr. John Choi is an outstanding hematopathologist whose exceptional expertise in flow cytometry has made a lasting impact on the field,” said Vishnu Reddy, M.D., Wyatt and Susan Haskell Endowed Chair for Medical Excellence and a professor in the Division of Laboratory Medicine. “He is widely recognized not only for the excellence of his diagnostic interpretation, but also for his deep technical mastery of flow cytometric instrumentation. His introduction of Sony’s multispectral flow instrument significantly expanded the role of flow cytometry in the diagnosis of leukemia and myeloma, while also strengthening the capability for minimal residual disease detection in acute lymphoblastic leukemia. Through these contributions, Dr. Choi has advanced both clinical practice and patient care in meaningful and enduring ways.”
Choi has published more than 100 peer-reviewed articles and 20 book chapters with two main research focuses. One is clinically based and applies new approaches to diagnose difficult pathologic entities. The other is more bench science based and focuses on increasing our understanding of the transcription factor TCF3 and its relationship to normal and leukemic B cell development. He has two patents and has been involved in several clinical trials on oncology related drug research throughout his career. His teaching and lecturing resume is extensive.
“I have enjoyed my six years at UAB and the many opportunities to explore new technologies and ideas in hematopathology,” Choi said. “I will most miss the wonderful people that I have had the pleasure of meeting and working alongside, especially in the hematopathology section, administrative support staff, and clinical flow cytometry laboratory. As I leave my duties to the next generation of pathologists, I look forward to spending more time with my family (hopefully not annoying my wife too badly), traveling, learning more about AI, and tackling over a thousand fictional novels and computer games.”
“As he begins his new chapter, we extend our sincere gratitude for his distinguished service, his many contributions to the profession, and the legacy he leaves behind,” Reddy said. “May his retirement bring the same fulfillment and joy that his work has brought to so many others.”