This proposal is for renewal of our research training grant in Immunohematology and Transfusion Medicine initiated in 2001. It provides a highly organized venue for MDs and MD/PhDs who have completed their clinical training to obtain an intense research experience in this underrepresented field, within a didactic framework, with the goal of generating productive physician-scientists. The T32 also trains PhDs who wish to become PhD clinician-scientists in Laboratory Medicine with skills in basic research combined with an understanding of clinical translational needs. Sponsored by the Yale Department of Laboratory Medicine, it also provides an opportunity for MD-only candidates with minimal prior research experience to simultaneously pursue an additional degree, either the Investigative Medicine PhD or a Master's in Biomedical Engineering. The core laboratory experience is carried out with all trainees having a dedicated 'training committee'(similar to a graduate student thesis committee);special seminar series complement the core experience. Our interdisciplinary faculty includes 22 well-funded, experienced mentors from 7 different primary departments, all of whom, have a long history of collaboration and whose laboratories are experienced in the simultaneous training of post-doc MDs, post-doc PhDs and pre-doc PhDs. In the first cycle of the T32, there will have been five trainees - two graduated and the remainder ongoing. Both graduates (1 MD, 1PhD) have obtained academic faculty positions - one has a K08 award. Of the 3 ongoing (2 MD, 1PhD), the two MDs are pursuing higher research-directed degrees (1 Investigative Medicine PhD, the other a Master's in Bioengineering). There are 3 men and 2 women, one trainee is of Puerto Rican heritage. They have worked in 4 different laboratories representing 2 distinct departments. Based on this experience, we are requesting an increase from 2 to 4 postdoctoral training slots - we already have excellent candidates in the pipeline who would potentially occupy the requested 4 slots through 2008-09. In total, including research trainees on other funding mechanisms, there are 32 trainees in our 'greater'immunohematology research program. We see this program as filling an important research training need both at Yale and nationally. (End of Abstract)