This is a revised competitive renewal of NIH T32HL-07910 undid since 1999. The aim is to continue training the next generation of scientists in the clinically-relevant medical area of gene transfer for effective modulation of normal cell growth, and gene therapy. We request 4 pre- and 5 postdoctoral positions and 1 short term pre-doc slot for a minority student. Pre- and post-doctoral trainees will be trained 3-4 and 2-3 years, respectively. We assembled an outstanding group of 24 productive/interactive investigators from 8 departments of the medical school (Microbiology/Immunology, Biochemistry/Molecular Biology, Pharmacology/Toxicology, Medical/ Mol-cular Genetics, Medicine, Pediatrics, General Surgery and Urology) who have trained pre- and/or post-doctorals with multidisciplinary approaches using different cell types. Training emphasis is on hematopoietic stem (HSC) cells and blood cells, but includes studies with other cell types for gene modification to enhance collaboration/training experiences. The PI studies HSC, hematopoietic, and gene replacement, published >640 papers ,is on numerous editorial boards/NIH/other review/advisory committees, is cun'ent Pres-Elect of ASH, trained 66 pre/post docs. The Co-PI is recognized in the gene therapy and viral vector production area, has published >100 refereed papers in these areas, is Pres-Elect of ASGT, has trained >10 students/fellows. The PI/Co-PI are part of a long-term funded PPG on gene therapy along with 6 other preceptors on the program, and the program includes a nationally- recognized and funded clinical grade gene vector production facility. Our preceptors have extensive collaboration , co-publish with each other, have all labs within 5-10 minute walking distance and are dedicated to training students in gene transfer/therapy. Training entails one-on-one interactions, formal committee meetings, lab meetings, special seminar series, didactic courses, ethical training and scientific meeting presentations. An Internal and External Advisory Committee will monitor student/mentor progress. Our past students are employed in academia, and biotech and pharmaceutical companies. This training will enhance the future of gene transfer/therapy for basic understanding and treatment of disease.