This is a revised application for a renewal of the Baylor College of Medicine (BCM) Hematology Training Grant that has been successfully running for 5 years and has trained, or is training, 23 young investigators, 5 of whom are from under-represented minorities. These trainees have published a total of 65 papers directly related to their hematology training. All of our trainees have advanced substantially in their biomedical research careers, and one has become a tenured Associate Professor at BCM, and four others have junior faculty positions. The overall goal of the BCM Hematology Training Program (HTP) supported through this Grant is to foster and strengthen the research base for trainees in basic and clinical research disciplines of Hematology. Training is provided to researchers in both adult and pediatric hematology who include MD, MD/PhD and PhD trainees. The BCM HTP provides its trainees with the mentorship, research skills and experience to ultimately become productive and successful investigators in the field. The program is structured to ensure close mentorship from accomplished senior researchers at Baylor College of Medicine, and to support junior faculty to develop their own mentorship skills. The 31 faculty mentors participating in the HTP have vast teaching and training experience and share a sincere commitment to train young physician scientists in hematology research. Their expertise covers a wide range of hematology research areas including stem cell biology, hemoglobin function, iron metabolism, thrombosis, neutrophil function, myeloid cell differentiation, stem cell transplantation and cell and gene therapy. Important components of the BCM HTP are a structured training scheme involving mentored research, a didactic program, and preparation for grant writing. The PI and Co-Directors, Margaret Goodell, David Poplack, and Martha Mims have a history of close productive interaction with each other and a strong record of past trainees, assuring a close interaction and integration of basic research with clinical adult and pediatric hematology programs. Renewal of the Hematology Training Program will ensure continued training of outstanding physician-scientists in hematology at BCM.