Project Summary/Abstract This application from Columbia University requests a third competitive renewal of a postdoctoral training program in digestive and liver diseases. The program, last reviewed in October 2018, is designed to provide research training opportunities for physician-scientist trainees in Gastroenterology-based fellowship programs, to prepare them into becoming independent basic, clinical and translational investigators. The T32 program, which has been in existence for fourteen years, takes advantage of many of the existing strengths of Columbia University, including a number of Centers and Departments and the broad framework of research at the university. The program has a long record of success, with >80% of the trainees that completed the program currently in academic positions at top universities and medical centers in the U.S., most with external funding. A major strength of the program is the highly collaborative and well-funded faculty as well as the many recent faculty recruits and the new, NIH-funded Digestive and Liver Diseases Research Center at Columbia. In addition, the training program builds on the highly academically oriented residency and fellowship programs in both adult and pediatric gastroenterology. Our trainees are selected from a very large pool of outstanding applicants to these clinical training programs. Special efforts have been undertaken to enhance our recruitment of women and minorities, aided by recent structural changes to our program; and the mentoring of women and minority trainees has thus become a major focus of the program. Dr. Timothy C. Wang is the PI and Director of this training program, ably assisted by Associate Director Dr. Howard Worman; and both have actively mentored young basic and clinical scientists for many years with superb track records in training. They are assisted by other members of the Executive Committee and supported by both Internal and External Advisory Committees. Trainees have a wide choice of mentors in basic GI, basic liver, or clinical/epidemiological research, and in addition to exciting research projects, they also complete a rigorous program of didactic instruction that includes cross training and multidisciplinary education. Many of our trainees will pursue training in Patient Oriented Research (POR) and obtain a Masters (MSc) degree. Key milestones for our trainees include publications, especially first-authored papers, and applications for career-development awards such as K awards and later R01 awards. The training program and associated departments have a well-established seminar series and journal clubs/workshops, career development and mentoring program, and an efficient feedback and evaluation system. In summary, this is a highly successful research training program of physician-scientists in digestive and liver diseases.