This proposal requests continued support for a long-standing postdoctoral training program in the basic science of cancer. The overall goal of this program is to prepare postdoctoral scientists for independent careers in basic and/or translational research focused on cancer. The trainees will be mentored by 50 faculty drawn from the three divisions (Basic, Medical, and Population Sciences) at the Fox Chase Cancer Center (FCCC). The faculty at FCCC are recognized leaders in their respective fields and maintain well-funded programs in diverse areas of research such as cell cycle regulation, signal transduction, protein biochemistry, developmental therapeutics and tumor cell biology. The training program is built on the broad-based principle that understanding cancer requires basic knowledge in biochemistry, molecular cell biology, and genetics. In addition to laboratory-based training, program-specific training includes a postdoctoral seminar series, a Center-wide journal club, and a Fellows Symposium, which is organized and implemented by the trainees in this program. Institution-specific training includes several seminar and lecture series, a bi-yearly faculty retreat and an annual Postdoctoral Fellows Day, along with grants-writing workshops and education series. As this training grant is the only active cancer biology training program at FCCC, it plays a central role in the development of our young scientists. This postdoctoral program is requesting support for 10 appointments, each of two years duration, with leadership provided by the Postdoctoral Review Committee at FCCC. Postdoctoral fellows are chosen from applicants based on NRSA-styled criteria including productivity and commitment to careers in cancer research. Notably, this training program in cancer research has been highly successful;we routinely have up to three times more applicants than positions available, we have never had a slot unfilled, and over 30% of our trainees in the past ten years now hold independent academic professorships in science. Our commitment to the training of postdoctoral fellows has not gone unnoticed;in the year 2004, Fox Chase Cancer Center was voted the "Best Place in Academia for Postdoctoral Fellows" by The Scientist magazine.