ABSTRACT This T32 Training Grant has for nearly four decades focused on the successful training of research-oriented pathologist-scientists in the Department of Pathology at the Massachusetts General Hospital. Over the past two five-year funding periods, trainees have published a considerable number of papers, including many in high quality journals, and have competed successfully for faculty positions in prestigious universities and medical schools and for research-focused positions in industry. The mentors of this current proposal comprise 32 Harvard and Massachusetts Institute of Technology faculty who are primarily centered in the Department of Pathology and Cancer Center at the Massachusetts General Hospital. This interactive community of fundamental researchers and physician-scientists is organized into thematic programs that include: cancer genetics; computational biology and bioinformatics; immunology and immunotherapy; in vivo imaging for cancer biology and diagnostics; chemical and functional genomics; epigenetics; cell cycle control and DNA damage; animal models of cancer; tissue, cell, and genome engineering; and single cell cancer genomics. As in previous cycles, the trainees will be selected from a highly competitive pool of M.D., M.D-Ph.D. and Ph.D. applicants on the basis of prior academic and research achievements and evidence of a strong commitment to a career in cancer biology. The period of training will be two or three years for each successful applicant. An active and program-specific recruitment and retention program to enhance diversity ensures that diverse applicants have access to, and will succeed in, the training program. In summary, the proposed T32 program renewal capitalizes on a highly interactive, experienced and focused faculty; a distinguished record of training productive physicians and scientists, including underrepresented minorities; state-of-the-art facilities and educational resources; and exposure of the trainees to basic and translational aspects of cancer biology.